Class BigDecimal
- java.lang.Object
-
- java.lang.Number
-
- java.math.BigDecimal
- All Implemented Interfaces:
-
Serializable
,Comparable<BigDecimal>
public class BigDecimal extends Number implements Comparable<BigDecimal>
Immutable, arbitrary-precision signed decimal numbers. A BigDecimal
consists of an arbitrary precision integer unscaled value and a 32-bit integer scale. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. The value of the number represented by the BigDecimal
is therefore (unscaledValue × 10-scale)
.
The BigDecimal
class provides operations for arithmetic, scale manipulation, rounding, comparison, hashing, and format conversion. The toString()
method provides a canonical representation of a BigDecimal
.
The BigDecimal
class gives its user complete control over rounding behavior. If no rounding mode is specified and the exact result cannot be represented, an exception is thrown; otherwise, calculations can be carried out to a chosen precision and rounding mode by supplying an appropriate MathContext
object to the operation. In either case, eight rounding modes are provided for the control of rounding. Using the integer fields in this class (such as ROUND_HALF_UP
) to represent rounding mode is deprecated; the enumeration values of the RoundingMode
enum
, (such as RoundingMode.HALF_UP
) should be used instead.
When a MathContext
object is supplied with a precision setting of 0 (for example, MathContext.UNLIMITED
), arithmetic operations are exact, as are the arithmetic methods which take no MathContext
object. (This is the only behavior that was supported in releases prior to 5.) As a corollary of computing the exact result, the rounding mode setting of a MathContext
object with a precision setting of 0 is not used and thus irrelevant. In the case of divide, the exact quotient could have an infinitely long decimal expansion; for example, 1 divided by 3. If the quotient has a nonterminating decimal expansion and the operation is specified to return an exact result, an ArithmeticException
is thrown. Otherwise, the exact result of the division is returned, as done for other operations.
When the precision setting is not 0, the rules of BigDecimal
arithmetic are broadly compatible with selected modes of operation of the arithmetic defined in ANSI X3.274-1996 and ANSI X3.274-1996/AM 1-2000 (section 7.4). Unlike those standards, BigDecimal
includes many rounding modes, which were mandatory for division in BigDecimal
releases prior to 5. Any conflicts between these ANSI standards and the BigDecimal
specification are resolved in favor of BigDecimal
.
Since the same numerical value can have different representations (with different scales), the rules of arithmetic and rounding must specify both the numerical result and the scale used in the result's representation.
In general the rounding modes and precision setting determine how operations return results with a limited number of digits when the exact result has more digits (perhaps infinitely many in the case of division and square root) than the number of digits returned. First, the total number of digits to return is specified by the MathContext
's precision
setting; this determines the result's precision. The digit count starts from the leftmost nonzero digit of the exact result. The rounding mode determines how any discarded trailing digits affect the returned result.
For all arithmetic operators , the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading "9" digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×101. In such cases, the new "1" is the leading digit position of the returned result.
Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.
Operation | Preferred Scale of Result |
---|---|
Add | max(addend.scale(), augend.scale()) |
Subtract | max(minuend.scale(), subtrahend.scale()) |
Multiply | multiplier.scale() + multiplicand.scale() |
Divide | dividend.scale() - divisor.scale() |
Square root | radicand.scale()/2 |
1/32
is 0.03125
. Before rounding, the scale of the logical exact intermediate result is the preferred scale for that operation. If the exact numerical result cannot be represented in precision
digits, rounding selects the set of digits to return and the scale of the result is reduced from the scale of the intermediate result to the least scale which can represent the precision
digits actually returned. If the exact result can be represented with at most precision
digits, the representation of the result with the scale closest to the preferred scale is returned. In particular, an exactly representable quotient may be represented in fewer than precision
digits by removing trailing zeros and decreasing the scale. For example, rounding to three digits using the floor rounding mode,
19/100 = 0.19 // integer=19, scale=2
but
21/110 = 0.190 // integer=190, scale=3
Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new high-order digit position, an additional digit of the result is discarded than when no new digit position is created.
Other methods may have slightly different rounding semantics. For example, the result of the pow
method using the specified algorithm can occasionally differ from the rounded mathematical result by more than one unit in the last place, one ulp.
Two types of operations are provided for manipulating the scale of a BigDecimal
: scaling/rounding operations and decimal point motion operations. Scaling/rounding operations (setScale
and round
) return a BigDecimal
whose value is approximately (or exactly) equal to that of the operand, but whose scale or precision is the specified value; that is, they increase or decrease the precision of the stored number with minimal effect on its value. Decimal point motion operations (movePointLeft
and movePointRight
) return a BigDecimal
created from the operand by moving the decimal point a specified distance in the specified direction.
For the sake of brevity and clarity, pseudo-code is used throughout the descriptions of BigDecimal
methods. The pseudo-code expression (i + j)
is shorthand for "a BigDecimal
whose value is that of the BigDecimal
i
added to that of the BigDecimal
j
." The pseudo-code expression (i == j)
is shorthand for "true
if and only if the BigDecimal
i
represents the same value as the BigDecimal
j
." Other pseudo-code expressions are interpreted similarly. Square brackets are used to represent the particular BigInteger
and scale pair defining a BigDecimal
value; for example [19, 2] is the BigDecimal
numerically equal to 0.19 having a scale of 2.
All methods and constructors for this class throw NullPointerException
when passed a null
object reference for any input parameter.
- API Note:
- Care should be exercised if
BigDecimal
objects are used as keys in aSortedMap
or elements in aSortedSet
sinceBigDecimal
's natural ordering is inconsistent with equals. SeeComparable
,SortedMap
orSortedSet
for more information. - Since:
- 1.1
- See Also:
-
BigInteger
,MathContext
,RoundingMode
,SortedMap
,SortedSet
, Serialized Form
Field Summary
Modifier and Type | Field | Description |
---|---|---|
static BigDecimal | ONE | The value 1, with a scale of 0. |
static int | ROUND_CEILING | Deprecated. Use RoundingMode.CEILING instead. |
static int | ROUND_DOWN | Deprecated. Use RoundingMode.DOWN instead. |
static int | ROUND_FLOOR | Deprecated. Use RoundingMode.FLOOR instead. |
static int | ROUND_HALF_DOWN | Deprecated. Use RoundingMode.HALF_DOWN instead. |
static int | ROUND_HALF_EVEN | Deprecated. Use RoundingMode.HALF_EVEN instead. |
static int | ROUND_HALF_UP | Deprecated. Use RoundingMode.HALF_UP instead. |
static int | ROUND_UNNECESSARY | Deprecated. Use RoundingMode.UNNECESSARY instead. |
static int | ROUND_UP | Deprecated. Use RoundingMode.UP instead. |
static BigDecimal | TEN | The value 10, with a scale of 0. |
static BigDecimal | ZERO | The value 0, with a scale of 0. |
Constructor Summary
Constructor | Description |
---|---|
BigDecimal(char[] in) | Translates a character array representation of a |
BigDecimal(char[] in,
int offset,
int len) | Translates a character array representation of a |
BigDecimal(char[] in,
int offset,
int len,
MathContext mc) | Translates a character array representation of a |
BigDecimal(char[] in,
MathContext mc) | Translates a character array representation of a |
BigDecimal(double val) | Translates a |
BigDecimal(double val,
MathContext mc) | Translates a |
BigDecimal(int val) | Translates an |
BigDecimal(int val,
MathContext mc) | Translates an |
BigDecimal(long val) | Translates a |
BigDecimal(long val,
MathContext mc) | Translates a |
BigDecimal(String val) | Translates the string representation of a |
BigDecimal(String val,
MathContext mc) | Translates the string representation of a |
BigDecimal(BigInteger val) | Translates a |
BigDecimal(BigInteger unscaledVal,
int scale) | Translates a |
BigDecimal(BigInteger unscaledVal,
int scale,
MathContext mc) | Translates a |
BigDecimal(BigInteger val,
MathContext mc) | Translates a |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
BigDecimal | abs() | Returns a |
BigDecimal | abs(MathContext mc) | Returns a |
BigDecimal | add(BigDecimal augend) | Returns a |
BigDecimal | add(BigDecimal augend,
MathContext mc) | Returns a |
byte | byteValueExact() | Converts this |
int | compareTo(BigDecimal val) | Compares this |
BigDecimal | divide(BigDecimal divisor) | Returns a |
BigDecimal | divide(BigDecimal divisor,
int roundingMode) | Deprecated. The method divide(BigDecimal, RoundingMode) should be used in preference to this legacy method. |
BigDecimal | divide(BigDecimal divisor,
int scale,
int roundingMode) | Deprecated. The method divide(BigDecimal, int, RoundingMode) should be used in preference to this legacy method. |
BigDecimal | divide(BigDecimal divisor,
int scale,
RoundingMode roundingMode) | Returns a |
BigDecimal | divide(BigDecimal divisor,
MathContext mc) | Returns a |
BigDecimal | divide(BigDecimal divisor,
RoundingMode roundingMode) | Returns a |
BigDecimal[] | divideAndRemainder(BigDecimal divisor) | Returns a two-element |
BigDecimal[] | divideAndRemainder(BigDecimal divisor,
MathContext mc) | Returns a two-element |
BigDecimal | divideToIntegralValue(BigDecimal divisor) | Returns a |
BigDecimal | divideToIntegralValue(BigDecimal divisor,
MathContext mc) | Returns a |
double | doubleValue() | Converts this |
boolean | equals(Object x) | Compares this |
float | floatValue() | Converts this |
int | hashCode() | Returns the hash code for this |
int | intValue() | Converts this |
int | intValueExact() | Converts this |
long | longValue() | Converts this |
long | longValueExact() | Converts this |
BigDecimal | max(BigDecimal val) | Returns the maximum of this |
BigDecimal | min(BigDecimal val) | Returns the minimum of this |
BigDecimal | movePointLeft(int n) | Returns a |
BigDecimal | movePointRight(int n) | Returns a |
BigDecimal | multiply(BigDecimal multiplicand) | Returns a |
BigDecimal | multiply(BigDecimal multiplicand,
MathContext mc) | Returns a |
BigDecimal | negate() | Returns a |
BigDecimal | negate(MathContext mc) | Returns a |
BigDecimal | plus() | Returns a |
BigDecimal | plus(MathContext mc) | Returns a |
BigDecimal | pow(int n) | Returns a |
BigDecimal | pow(int n,
MathContext mc) | Returns a |
int | precision() | Returns the precision of this |
BigDecimal | remainder(BigDecimal divisor) | Returns a |
BigDecimal | remainder(BigDecimal divisor,
MathContext mc) | Returns a |
BigDecimal | round(MathContext mc) | Returns a |
int | scale() | Returns the scale of this |
BigDecimal | scaleByPowerOfTen(int n) | Returns a BigDecimal whose numerical value is equal to ( |
BigDecimal | setScale(int newScale) | Returns a |
BigDecimal | setScale(int newScale,
int roundingMode) | Deprecated. The method setScale(int, RoundingMode) should be used in preference to this legacy method. |
BigDecimal | setScale(int newScale,
RoundingMode roundingMode) | Returns a |
short | shortValueExact() | Converts this |
int | signum() | Returns the signum function of this |
BigDecimal | sqrt(MathContext mc) | Returns an approximation to the square root of |
BigDecimal | stripTrailingZeros() | Returns a |
BigDecimal | subtract(BigDecimal subtrahend) | Returns a |
BigDecimal | subtract(BigDecimal subtrahend,
MathContext mc) | Returns a |
BigInteger | toBigInteger() | Converts this |
BigInteger | toBigIntegerExact() | Converts this |
String | toEngineeringString() | Returns a string representation of this |
String | toPlainString() | Returns a string representation of this |
String | toString() | Returns the string representation of this |
BigDecimal | ulp() | Returns the size of an ulp, a unit in the last place, of this |
BigInteger | unscaledValue() | Returns a |
static BigDecimal | valueOf(double val) | Translates a |
static BigDecimal | valueOf(long val) | Translates a |
static BigDecimal | valueOf(long unscaledVal,
int scale) | Translates a |
Methods declared in class java.lang.Number
byteValue, shortValue
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Field Detail
ZERO
public static final BigDecimal ZERO
The value 0, with a scale of 0.
- Since:
- 1.5
ONE
public static final BigDecimal ONE
The value 1, with a scale of 0.
- Since:
- 1.5
TEN
public static final BigDecimal TEN
The value 10, with a scale of 0.
- Since:
- 1.5
ROUND_UP
@Deprecated(since="9") public static final int ROUND_UP
RoundingMode.UP
instead.Rounding mode to round away from zero. Always increments the digit prior to a nonzero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value.
- See Also:
- Constant Field Values
ROUND_DOWN
@Deprecated(since="9") public static final int ROUND_DOWN
RoundingMode.DOWN
instead.Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value.
- See Also:
- Constant Field Values
ROUND_CEILING
@Deprecated(since="9") public static final int ROUND_CEILING
RoundingMode.CEILING
instead.Rounding mode to round towards positive infinity. If the BigDecimal
is positive, behaves as for ROUND_UP
; if negative, behaves as for ROUND_DOWN
. Note that this rounding mode never decreases the calculated value.
- See Also:
- Constant Field Values
ROUND_FLOOR
@Deprecated(since="9") public static final int ROUND_FLOOR
RoundingMode.FLOOR
instead.Rounding mode to round towards negative infinity. If the BigDecimal
is positive, behave as for ROUND_DOWN
; if negative, behave as for ROUND_UP
. Note that this rounding mode never increases the calculated value.
- See Also:
- Constant Field Values
ROUND_HALF_UP
@Deprecated(since="9") public static final int ROUND_HALF_UP
RoundingMode.HALF_UP
instead.Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. Behaves as for ROUND_UP
if the discarded fraction is ≥ 0.5; otherwise, behaves as for ROUND_DOWN
. Note that this is the rounding mode that most of us were taught in grade school.
- See Also:
- Constant Field Values
ROUND_HALF_DOWN
@Deprecated(since="9") public static final int ROUND_HALF_DOWN
RoundingMode.HALF_DOWN
instead.Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. Behaves as for ROUND_UP
if the discarded fraction is > 0.5; otherwise, behaves as for ROUND_DOWN
.
- See Also:
- Constant Field Values
ROUND_HALF_EVEN
@Deprecated(since="9") public static final int ROUND_HALF_EVEN
RoundingMode.HALF_EVEN
instead.Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. Behaves as for ROUND_HALF_UP
if the digit to the left of the discarded fraction is odd; behaves as for ROUND_HALF_DOWN
if it's even. Note that this is the rounding mode that minimizes cumulative error when applied repeatedly over a sequence of calculations.
- See Also:
- Constant Field Values
ROUND_UNNECESSARY
@Deprecated(since="9") public static final int ROUND_UNNECESSARY
RoundingMode.UNNECESSARY
instead.Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, an ArithmeticException
is thrown.
- See Also:
- Constant Field Values
Constructor Detail
BigDecimal
public BigDecimal(char[] in, int offset, int len)
Translates a character array representation of a BigDecimal
into a BigDecimal
, accepting the same sequence of characters as the BigDecimal(String)
constructor, while allowing a sub-array to be specified.
- Implementation Note:
- If the sequence of characters is already available within a character array, using this constructor is faster than converting the
char
array to string and using theBigDecimal(String)
constructor. - Parameters:
-
in
-char
array that is the source of characters. -
offset
- first character in the array to inspect. -
len
- number of characters to consider. - Throws:
-
NumberFormatException
- ifin
is not a valid representation of aBigDecimal
or the defined subarray is not wholly withinin
. - Since:
- 1.5
BigDecimal
public BigDecimal(char[] in, int offset, int len, MathContext mc)
Translates a character array representation of a BigDecimal
into a BigDecimal
, accepting the same sequence of characters as the BigDecimal(String)
constructor, while allowing a sub-array to be specified and with rounding according to the context settings.
- Implementation Note:
- If the sequence of characters is already available within a character array, using this constructor is faster than converting the
char
array to string and using theBigDecimal(String)
constructor. - Parameters:
-
in
-char
array that is the source of characters. -
offset
- first character in the array to inspect. -
len
- number of characters to consider. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. -
NumberFormatException
- ifin
is not a valid representation of aBigDecimal
or the defined subarray is not wholly withinin
. - Since:
- 1.5
BigDecimal
public BigDecimal(char[] in)
Translates a character array representation of a BigDecimal
into a BigDecimal
, accepting the same sequence of characters as the BigDecimal(String)
constructor.
- Implementation Note:
- If the sequence of characters is already available as a character array, using this constructor is faster than converting the
char
array to string and using theBigDecimal(String)
constructor. - Parameters:
-
in
-char
array that is the source of characters. - Throws:
-
NumberFormatException
- ifin
is not a valid representation of aBigDecimal
. - Since:
- 1.5
BigDecimal
public BigDecimal(char[] in, MathContext mc)
Translates a character array representation of a BigDecimal
into a BigDecimal
, accepting the same sequence of characters as the BigDecimal(String)
constructor and with rounding according to the context settings.
- Implementation Note:
- If the sequence of characters is already available as a character array, using this constructor is faster than converting the
char
array to string and using theBigDecimal(String)
constructor. - Parameters:
-
in
-char
array that is the source of characters. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. -
NumberFormatException
- ifin
is not a valid representation of aBigDecimal
. - Since:
- 1.5
BigDecimal
public BigDecimal(String val)
Translates the string representation of a BigDecimal
into a BigDecimal
. The string representation consists of an optional sign, '+'
( '\u002B'
) or '-'
('\u002D'
), followed by a sequence of zero or more decimal digits ("the integer"), optionally followed by a fraction, optionally followed by an exponent.
The fraction consists of a decimal point followed by zero or more decimal digits. The string must contain at least one digit in either the integer or the fraction. The number formed by the sign, the integer and the fraction is referred to as the significand.
The exponent consists of the character 'e'
('\u0065'
) or 'E'
('\u0045'
) followed by one or more decimal digits. The value of the exponent must lie between -Integer.MAX_VALUE
(Integer.MIN_VALUE
+1) and Integer.MAX_VALUE
, inclusive.
More formally, the strings this constructor accepts are described by the following grammar:
- BigDecimalString:
- Signopt Significand Exponentopt
- Sign:
-
+
-
- Significand:
-
IntegerPart
.
FractionPartopt.
FractionPart- IntegerPart
- IntegerPart:
- Digits
- FractionPart:
- Digits
- Exponent:
- ExponentIndicator SignedInteger
- ExponentIndicator:
-
e
E
- SignedInteger:
- Signopt Digits
- Digits:
-
Digit
- Digits Digit
- Digit:
- any character for which
Character.isDigit(char)
returnstrue
, including 0, 1, 2 ...
The scale of the returned BigDecimal
will be the number of digits in the fraction, or zero if the string contains no decimal point, subject to adjustment for any exponent; if the string contains an exponent, the exponent is subtracted from the scale. The value of the resulting scale must lie between Integer.MIN_VALUE
and Integer.MAX_VALUE
, inclusive.
The character-to-digit mapping is provided by Character.digit(char, int)
set to convert to radix 10. The String may not contain any extraneous characters (whitespace, for example).
Examples:
The value of the returned BigDecimal
is equal to significand × 10 exponent. For each string on the left, the resulting representation [BigInteger
, scale
] is shown on the right.
"0" [0,0] "0.00" [0,2] "123" [123,0] "-123" [-123,0] "1.23E3" [123,-1] "1.23E+3" [123,-1] "12.3E+7" [123,-6] "12.0" [120,1] "12.3" [123,1] "0.00123" [123,5] "-1.23E-12" [-123,14] "1234.5E-4" [12345,5] "0E+7" [0,-7] "-0" [0,0]
- API Note:
- For values other than
float
anddouble
NaN and ±Infinity, this constructor is compatible with the values returned byFloat.toString(float)
andDouble.toString(double)
. This is generally the preferred way to convert afloat
ordouble
into a BigDecimal, as it doesn't suffer from the unpredictability of theBigDecimal(double)
constructor. - Parameters:
-
val
- String representation ofBigDecimal
. - Throws:
-
NumberFormatException
- ifval
is not a valid representation of aBigDecimal
.
BigDecimal
public BigDecimal(String val, MathContext mc)
Translates the string representation of a BigDecimal
into a BigDecimal
, accepting the same strings as the BigDecimal(String)
constructor, with rounding according to the context settings.
- Parameters:
-
val
- string representation of aBigDecimal
. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. -
NumberFormatException
- ifval
is not a valid representation of a BigDecimal. - Since:
- 1.5
BigDecimal
public BigDecimal(double val)
Translates a double
into a BigDecimal
which is the exact decimal representation of the double
's binary floating-point value. The scale of the returned BigDecimal
is the smallest value such that (10scale × val)
is an integer.
Notes:
- The results of this constructor can be somewhat unpredictable. One might assume that writing
new BigDecimal(0.1)
in Java creates aBigDecimal
which is exactly equal to 0.1 (an unscaled value of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625. This is because 0.1 cannot be represented exactly as adouble
(or, for that matter, as a binary fraction of any finite length). Thus, the value that is being passed in to the constructor is not exactly equal to 0.1, appearances notwithstanding. - The
String
constructor, on the other hand, is perfectly predictable: writingnew BigDecimal("0.1")
creates aBigDecimal
which is exactly equal to 0.1, as one would expect. Therefore, it is generally recommended that the String constructor be used in preference to this one. - When a
double
must be used as a source for aBigDecimal
, note that this constructor provides an exact conversion; it does not give the same result as converting thedouble
to aString
using theDouble.toString(double)
method and then using theBigDecimal(String)
constructor. To get that result, use thestatic
valueOf(double)
method.
- Parameters:
-
val
-double
value to be converted toBigDecimal
. - Throws:
-
NumberFormatException
- ifval
is infinite or NaN.
BigDecimal
public BigDecimal(double val, MathContext mc)
Translates a double
into a BigDecimal
, with rounding according to the context settings. The scale of the BigDecimal
is the smallest value such that (10scale × val)
is an integer.
The results of this constructor can be somewhat unpredictable and its use is generally not recommended; see the notes under the BigDecimal(double)
constructor.
- Parameters:
-
val
-double
value to be converted toBigDecimal
. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the RoundingMode is UNNECESSARY. -
NumberFormatException
- ifval
is infinite or NaN. - Since:
- 1.5
BigDecimal
public BigDecimal(BigInteger val)
Translates a BigInteger
into a BigDecimal
. The scale of the BigDecimal
is zero.
- Parameters:
-
val
-BigInteger
value to be converted toBigDecimal
.
BigDecimal
public BigDecimal(BigInteger val, MathContext mc)
Translates a BigInteger
into a BigDecimal
rounding according to the context settings. The scale of the BigDecimal
is zero.
- Parameters:
-
val
-BigInteger
value to be converted toBigDecimal
. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
BigDecimal
public BigDecimal(BigInteger unscaledVal, int scale)
Translates a BigInteger
unscaled value and an int
scale into a BigDecimal
. The value of the BigDecimal
is (unscaledVal × 10-scale)
.
- Parameters:
-
unscaledVal
- unscaled value of theBigDecimal
. -
scale
- scale of theBigDecimal
.
BigDecimal
public BigDecimal(BigInteger unscaledVal, int scale, MathContext mc)
Translates a BigInteger
unscaled value and an int
scale into a BigDecimal
, with rounding according to the context settings. The value of the BigDecimal
is (unscaledVal ×
10-scale)
, rounded according to the precision
and rounding mode settings.
- Parameters:
-
unscaledVal
- unscaled value of theBigDecimal
. -
scale
- scale of theBigDecimal
. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
BigDecimal
public BigDecimal(int val)
Translates an int
into a BigDecimal
. The scale of the BigDecimal
is zero.
- Parameters:
-
val
-int
value to be converted toBigDecimal
. - Since:
- 1.5
BigDecimal
public BigDecimal(int val, MathContext mc)
Translates an int
into a BigDecimal
, with rounding according to the context settings. The scale of the BigDecimal
, before any rounding, is zero.
- Parameters:
-
val
-int
value to be converted toBigDecimal
. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
BigDecimal
public BigDecimal(long val)
Translates a long
into a BigDecimal
. The scale of the BigDecimal
is zero.
- Parameters:
-
val
-long
value to be converted toBigDecimal
. - Since:
- 1.5
BigDecimal
public BigDecimal(long val, MathContext mc)
Translates a long
into a BigDecimal
, with rounding according to the context settings. The scale of the BigDecimal
, before any rounding, is zero.
- Parameters:
-
val
-long
value to be converted toBigDecimal
. -
mc
- the context to use. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
Method Detail
valueOf
public static BigDecimal valueOf(long unscaledVal, int scale)
Translates a long
unscaled value and an int
scale into a BigDecimal
.
- API Note:
- This static factory method is provided in preference to a (
long
,int
) constructor because it allows for reuse of frequently usedBigDecimal
values. - Parameters:
-
unscaledVal
- unscaled value of theBigDecimal
. -
scale
- scale of theBigDecimal
. - Returns:
- a
BigDecimal
whose value is(unscaledVal × 10-scale)
.
valueOf
public static BigDecimal valueOf(long val)
Translates a long
value into a BigDecimal
with a scale of zero.
- API Note:
- This static factory method is provided in preference to a (
long
) constructor because it allows for reuse of frequently usedBigDecimal
values. - Parameters:
-
val
- value of theBigDecimal
. - Returns:
- a
BigDecimal
whose value isval
.
valueOf
public static BigDecimal valueOf(double val)
Translates a double
into a BigDecimal
, using the double
's canonical string representation provided by the Double.toString(double)
method.
- API Note:
- This is generally the preferred way to convert a
double
(orfloat
) into aBigDecimal
, as the value returned is equal to that resulting from constructing aBigDecimal
from the result of usingDouble.toString(double)
. - Parameters:
-
val
-double
to convert to aBigDecimal
. - Returns:
- a
BigDecimal
whose value is equal to or approximately equal to the value ofval
. - Throws:
-
NumberFormatException
- ifval
is infinite or NaN. - Since:
- 1.5
add
public BigDecimal add(BigDecimal augend)
Returns a BigDecimal
whose value is (this +
augend)
, and whose scale is max(this.scale(),
augend.scale())
.
- Parameters:
-
augend
- value to be added to thisBigDecimal
. - Returns:
this + augend
add
public BigDecimal add(BigDecimal augend, MathContext mc)
Returns a BigDecimal
whose value is (this + augend)
, with rounding according to the context settings. If either number is zero and the precision setting is nonzero then the other number, rounded if necessary, is used as the result.
- Parameters:
-
augend
- value to be added to thisBigDecimal
. -
mc
- the context to use. - Returns:
-
this + augend
, rounded as necessary. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
subtract
public BigDecimal subtract(BigDecimal subtrahend)
Returns a BigDecimal
whose value is (this -
subtrahend)
, and whose scale is max(this.scale(),
subtrahend.scale())
.
- Parameters:
-
subtrahend
- value to be subtracted from thisBigDecimal
. - Returns:
this - subtrahend
subtract
public BigDecimal subtract(BigDecimal subtrahend, MathContext mc)
Returns a BigDecimal
whose value is (this - subtrahend)
, with rounding according to the context settings. If subtrahend
is zero then this, rounded if necessary, is used as the result. If this is zero then the result is subtrahend.negate(mc)
.
- Parameters:
-
subtrahend
- value to be subtracted from thisBigDecimal
. -
mc
- the context to use. - Returns:
-
this - subtrahend
, rounded as necessary. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
multiply
public BigDecimal multiply(BigDecimal multiplicand)
Returns a BigDecimal
whose value is (this ×
multiplicand)
, and whose scale is (this.scale() +
multiplicand.scale())
.
- Parameters:
-
multiplicand
- value to be multiplied by thisBigDecimal
. - Returns:
this * multiplicand
multiply
public BigDecimal multiply(BigDecimal multiplicand, MathContext mc)
Returns a BigDecimal
whose value is (this ×
multiplicand)
, with rounding according to the context settings.
- Parameters:
-
multiplicand
- value to be multiplied by thisBigDecimal
. -
mc
- the context to use. - Returns:
-
this * multiplicand
, rounded as necessary. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
divide
@Deprecated(since="9") public BigDecimal divide(BigDecimal divisor, int scale, int roundingMode)
divide(BigDecimal, int, RoundingMode)
should be used in preference to this legacy method.Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
scale
- scale of theBigDecimal
quotient to be returned. -
roundingMode
- rounding mode to apply. - Returns:
this / divisor
- Throws:
-
ArithmeticException
- ifdivisor
is zero,roundingMode==ROUND_UNNECESSARY
and the specified scale is insufficient to represent the result of the division exactly. -
IllegalArgumentException
- ifroundingMode
does not represent a valid rounding mode. - See Also:
-
ROUND_UP
,ROUND_DOWN
,ROUND_CEILING
,ROUND_FLOOR
,ROUND_HALF_UP
,ROUND_HALF_DOWN
,ROUND_HALF_EVEN
,ROUND_UNNECESSARY
divide
public BigDecimal divide(BigDecimal divisor, int scale, RoundingMode roundingMode)
Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
scale
- scale of theBigDecimal
quotient to be returned. -
roundingMode
- rounding mode to apply. - Returns:
this / divisor
- Throws:
-
ArithmeticException
- ifdivisor
is zero,roundingMode==RoundingMode.UNNECESSARY
and the specified scale is insufficient to represent the result of the division exactly. - Since:
- 1.5
divide
@Deprecated(since="9") public BigDecimal divide(BigDecimal divisor, int roundingMode)
divide(BigDecimal, RoundingMode)
should be used in preference to this legacy method.Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is this.scale()
. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
roundingMode
- rounding mode to apply. - Returns:
this / divisor
- Throws:
-
ArithmeticException
- ifdivisor==0
, orroundingMode==ROUND_UNNECESSARY
andthis.scale()
is insufficient to represent the result of the division exactly. -
IllegalArgumentException
- ifroundingMode
does not represent a valid rounding mode. - See Also:
-
ROUND_UP
,ROUND_DOWN
,ROUND_CEILING
,ROUND_FLOOR
,ROUND_HALF_UP
,ROUND_HALF_DOWN
,ROUND_HALF_EVEN
,ROUND_UNNECESSARY
divide
public BigDecimal divide(BigDecimal divisor, RoundingMode roundingMode)
Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is this.scale()
. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
roundingMode
- rounding mode to apply. - Returns:
this / divisor
- Throws:
-
ArithmeticException
- ifdivisor==0
, orroundingMode==RoundingMode.UNNECESSARY
andthis.scale()
is insufficient to represent the result of the division exactly. - Since:
- 1.5
divide
public BigDecimal divide(BigDecimal divisor)
Returns a BigDecimal
whose value is (this /
divisor)
, and whose preferred scale is (this.scale() -
divisor.scale())
; if the exact quotient cannot be represented (because it has a non-terminating decimal expansion) an ArithmeticException
is thrown.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. - Returns:
this / divisor
- Throws:
-
ArithmeticException
- if the exact quotient does not have a terminating decimal expansion - Since:
- 1.5
divide
public BigDecimal divide(BigDecimal divisor, MathContext mc)
Returns a BigDecimal
whose value is (this /
divisor)
, with rounding according to the context settings.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
mc
- the context to use. - Returns:
-
this / divisor
, rounded as necessary. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
ormc.precision == 0
and the quotient has a non-terminating decimal expansion. - Since:
- 1.5
divideToIntegralValue
public BigDecimal divideToIntegralValue(BigDecimal divisor)
Returns a BigDecimal
whose value is the integer part of the quotient (this / divisor)
rounded down. The preferred scale of the result is (this.scale() -
divisor.scale())
.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. - Returns:
- The integer part of
this / divisor
. - Throws:
-
ArithmeticException
- ifdivisor==0
- Since:
- 1.5
divideToIntegralValue
public BigDecimal divideToIntegralValue(BigDecimal divisor, MathContext mc)
Returns a BigDecimal
whose value is the integer part of (this / divisor)
. Since the integer part of the exact quotient does not depend on the rounding mode, the rounding mode does not affect the values returned by this method. The preferred scale of the result is (this.scale() - divisor.scale())
. An ArithmeticException
is thrown if the integer part of the exact quotient needs more than mc.precision
digits.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
mc
- the context to use. - Returns:
- The integer part of
this / divisor
. - Throws:
-
ArithmeticException
- ifdivisor==0
-
ArithmeticException
- ifmc.precision
> 0 and the result requires a precision of more thanmc.precision
digits. - Since:
- 1.5
remainder
public BigDecimal remainder(BigDecimal divisor)
Returns a BigDecimal
whose value is (this % divisor)
.
The remainder is given by this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative).
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. - Returns:
-
this % divisor
. - Throws:
-
ArithmeticException
- ifdivisor==0
- Since:
- 1.5
remainder
public BigDecimal remainder(BigDecimal divisor, MathContext mc)
Returns a BigDecimal
whose value is (this %
divisor)
, with rounding according to the context settings. The MathContext
settings affect the implicit divide used to compute the remainder. The remainder computation itself is by definition exact. Therefore, the remainder may contain more than mc.getPrecision()
digits.
The remainder is given by this.subtract(this.divideToIntegralValue(divisor,
mc).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative).
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided. -
mc
- the context to use. - Returns:
-
this % divisor
, rounded as necessary. - Throws:
-
ArithmeticException
- ifdivisor==0
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
, ormc.precision
> 0 and the result ofthis.divideToIntgralValue(divisor)
would require a precision of more thanmc.precision
digits. - Since:
- 1.5
- See Also:
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
divideAndRemainder
public BigDecimal[] divideAndRemainder(BigDecimal divisor)
Returns a two-element BigDecimal
array containing the result of divideToIntegralValue
followed by the result of remainder
on the two operands.
Note that if both the integer quotient and remainder are needed, this method is faster than using the divideToIntegralValue
and remainder
methods separately because the division need only be carried out once.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided, and the remainder computed. - Returns:
- a two element
BigDecimal
array: the quotient (the result ofdivideToIntegralValue
) is the initial element and the remainder is the final element. - Throws:
-
ArithmeticException
- ifdivisor==0
- Since:
- 1.5
- See Also:
-
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,remainder(java.math.BigDecimal, java.math.MathContext)
divideAndRemainder
public BigDecimal[] divideAndRemainder(BigDecimal divisor, MathContext mc)
Returns a two-element BigDecimal
array containing the result of divideToIntegralValue
followed by the result of remainder
on the two operands calculated with rounding according to the context settings.
Note that if both the integer quotient and remainder are needed, this method is faster than using the divideToIntegralValue
and remainder
methods separately because the division need only be carried out once.
- Parameters:
-
divisor
- value by which thisBigDecimal
is to be divided, and the remainder computed. -
mc
- the context to use. - Returns:
- a two element
BigDecimal
array: the quotient (the result ofdivideToIntegralValue
) is the initial element and the remainder is the final element. - Throws:
-
ArithmeticException
- ifdivisor==0
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
, ormc.precision
> 0 and the result ofthis.divideToIntgralValue(divisor)
would require a precision of more thanmc.precision
digits. - Since:
- 1.5
- See Also:
-
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,remainder(java.math.BigDecimal, java.math.MathContext)
sqrt
public BigDecimal sqrt(MathContext mc)
Returns an approximation to the square root of this
with rounding according to the context settings.
The preferred scale of the returned result is equal to this.scale()/2
. The value of the returned result is always within one ulp of the exact decimal value for the precision in question. If the rounding mode is HALF_UP
, HALF_DOWN
, or HALF_EVEN
, the result is within one half an ulp of the exact decimal value.
Special case:
- The square root of a number numerically equal to
ZERO
is numerically equal toZERO
with a preferred scale according to the general rule above. In particular, forZERO
,ZERO.sqrt(mc).equals(ZERO)
is true with anyMathContext
as an argument.
- Parameters:
-
mc
- the context to use. - Returns:
- the square root of
this
. - Throws:
-
ArithmeticException
- ifthis
is less than zero. -
ArithmeticException
- if an exact result is requested (mc.getPrecision()==0
) and there is no finite decimal expansion of the exact result -
ArithmeticException
- if(mc.getRoundingMode()==RoundingMode.UNNECESSARY
) and the exact result cannot fit inmc.getPrecision()
digits. - Since:
- 9
- See Also:
BigInteger.sqrt()
pow
public BigDecimal pow(int n)
Returns a BigDecimal
whose value is (thisn)
, The power is computed exactly, to unlimited precision.
The parameter n
must be in the range 0 through 999999999, inclusive. ZERO.pow(0)
returns ONE
. Note that future releases may expand the allowable exponent range of this method.
- Parameters:
-
n
- power to raise thisBigDecimal
to. - Returns:
thisn
- Throws:
-
ArithmeticException
- ifn
is out of range. - Since:
- 1.5
pow
public BigDecimal pow(int n, MathContext mc)
Returns a BigDecimal
whose value is (thisn)
. The current implementation uses the core algorithm defined in ANSI standard X3.274-1996 with rounding according to the context settings. In general, the returned numerical value is within two ulps of the exact numerical value for the chosen precision. Note that future releases may use a different algorithm with a decreased allowable error bound and increased allowable exponent range.
The X3.274-1996 algorithm is:
- An
ArithmeticException
exception is thrown if-
abs(n) > 999999999
-
mc.precision == 0
andn < 0
-
mc.precision > 0
andn
has more thanmc.precision
decimal digits
-
- if
n
is zero,ONE
is returned even ifthis
is zero, otherwise- if
n
is positive, the result is calculated via the repeated squaring technique into a single accumulator. The individual multiplications with the accumulator use the same math context settings as inmc
except for a precision increased tomc.precision + elength + 1
whereelength
is the number of decimal digits inn
. - if
n
is negative, the result is calculated as ifn
were positive; this value is then divided into one using the working precision specified above. - The final value from either the positive or negative case is then rounded to the destination precision.
- if
- Parameters:
-
n
- power to raise thisBigDecimal
to. -
mc
- the context to use. - Returns:
-
thisn
using the ANSI standard X3.274-1996 algorithm - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
, orn
is out of range. - Since:
- 1.5
abs
public BigDecimal abs()
Returns a BigDecimal
whose value is the absolute value of this BigDecimal
, and whose scale is this.scale()
.
- Returns:
abs(this)
abs
public BigDecimal abs(MathContext mc)
Returns a BigDecimal
whose value is the absolute value of this BigDecimal
, with rounding according to the context settings.
- Parameters:
-
mc
- the context to use. - Returns:
-
abs(this)
, rounded as necessary. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
negate
public BigDecimal negate()
Returns a BigDecimal
whose value is (-this)
, and whose scale is this.scale()
.
- Returns:
-
-this
.
negate
public BigDecimal negate(MathContext mc)
Returns a BigDecimal
whose value is (-this)
, with rounding according to the context settings.
- Parameters:
-
mc
- the context to use. - Returns:
-
-this
, rounded as necessary. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
plus
public BigDecimal plus()
Returns a BigDecimal
whose value is (+this)
, and whose scale is this.scale()
.
This method, which simply returns this BigDecimal
is included for symmetry with the unary minus method negate()
.
- Returns:
-
this
. - Since:
- 1.5
- See Also:
negate()
plus
public BigDecimal plus(MathContext mc)
Returns a BigDecimal
whose value is (+this)
, with rounding according to the context settings.
The effect of this method is identical to that of the round(MathContext)
method.
- Parameters:
-
mc
- the context to use. - Returns:
-
this
, rounded as necessary. A zero result will have a scale of 0. - Throws:
-
ArithmeticException
- if the result is inexact but the rounding mode isUNNECESSARY
. - Since:
- 1.5
- See Also:
round(MathContext)
signum
public int signum()
Returns the signum function of this BigDecimal
.
- Returns:
- -1, 0, or 1 as the value of this
BigDecimal
is negative, zero, or positive.
scale
public int scale()
Returns the scale of this BigDecimal
. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. For example, a scale of -3
means the unscaled value is multiplied by 1000.
- Returns:
- the scale of this
BigDecimal
.
precision
public int precision()
Returns the precision of this BigDecimal
. (The precision is the number of digits in the unscaled value.)
The precision of a zero value is 1.
- Returns:
- the precision of this
BigDecimal
. - Since:
- 1.5
unscaledValue
public BigInteger unscaledValue()
Returns a BigInteger
whose value is the unscaled value of this BigDecimal
. (Computes (this *
10this.scale())
.)
- Returns:
- the unscaled value of this
BigDecimal
. - Since:
- 1.2
round
public BigDecimal round(MathContext mc)
Returns a BigDecimal
rounded according to the MathContext
settings. If the precision setting is 0 then no rounding takes place.
The effect of this method is identical to that of the plus(MathContext)
method.
- Parameters:
-
mc
- the context to use. - Returns:
- a
BigDecimal
rounded according to theMathContext
settings. - Throws:
-
ArithmeticException
- if the rounding mode isUNNECESSARY
and theBigDecimal
operation would require rounding. - Since:
- 1.5
- See Also:
plus(MathContext)
setScale
public BigDecimal setScale(int newScale, RoundingMode roundingMode)
Returns a BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
- API Note:
- Since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named
setX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated. - Parameters:
-
newScale
- scale of theBigDecimal
value to be returned. -
roundingMode
- The rounding mode to apply. - Returns:
- a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. - Throws:
-
ArithmeticException
- ifroundingMode==UNNECESSARY
and the specified scaling operation would require rounding. - Since:
- 1.5
- See Also:
RoundingMode
setScale
@Deprecated(since="9") public BigDecimal setScale(int newScale, int roundingMode)
setScale(int, RoundingMode)
should be used in preference to this legacy method.Returns a BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
- API Note:
- Since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named
setX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated. - Parameters:
-
newScale
- scale of theBigDecimal
value to be returned. -
roundingMode
- The rounding mode to apply. - Returns:
- a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. - Throws:
-
ArithmeticException
- ifroundingMode==ROUND_UNNECESSARY
and the specified scaling operation would require rounding. -
IllegalArgumentException
- ifroundingMode
does not represent a valid rounding mode. - See Also:
-
ROUND_UP
,ROUND_DOWN
,ROUND_CEILING
,ROUND_FLOOR
,ROUND_HALF_UP
,ROUND_HALF_DOWN
,ROUND_HALF_EVEN
,ROUND_UNNECESSARY
setScale
public BigDecimal setScale(int newScale)
Returns a BigDecimal
whose scale is the specified value, and whose value is numerically equal to this BigDecimal
's. Throws an ArithmeticException
if this is not possible.
This call is typically used to increase the scale, in which case it is guaranteed that there exists a BigDecimal
of the specified scale and the correct value. The call can also be used to reduce the scale if the caller knows that the BigDecimal
has sufficiently many zeros at the end of its fractional part (i.e., factors of ten in its integer value) to allow for the rescaling without changing its value.
This method returns the same result as the two-argument versions of setScale
, but saves the caller the trouble of specifying a rounding mode in cases where it is irrelevant.
- API Note:
- Since
BigDecimal
objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods namedsetX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated. - Parameters:
-
newScale
- scale of theBigDecimal
value to be returned. - Returns:
- a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. - Throws:
-
ArithmeticException
- if the specified scaling operation would require rounding. - See Also:
-
setScale(int, int)
,setScale(int, RoundingMode)
movePointLeft
public BigDecimal movePointLeft(int n)
Returns a BigDecimal
which is equivalent to this one with the decimal point moved n
places to the left. If n
is non-negative, the call merely adds n
to the scale. If n
is negative, the call is equivalent to movePointRight(-n)
. The BigDecimal
returned by this call has value (this ×
10-n)
and scale max(this.scale()+n,
0)
.
- Parameters:
-
n
- number of places to move the decimal point to the left. - Returns:
- a
BigDecimal
which is equivalent to this one with the decimal point movedn
places to the left. - Throws:
-
ArithmeticException
- if scale overflows.
movePointRight
public BigDecimal movePointRight(int n)
Returns a BigDecimal
which is equivalent to this one with the decimal point moved n
places to the right. If n
is non-negative, the call merely subtracts n
from the scale. If n
is negative, the call is equivalent to movePointLeft(-n)
. The BigDecimal
returned by this call has value (this
× 10n)
and scale max(this.scale()-n,
0)
.
- Parameters:
-
n
- number of places to move the decimal point to the right. - Returns:
- a
BigDecimal
which is equivalent to this one with the decimal point movedn
places to the right. - Throws:
-
ArithmeticException
- if scale overflows.
scaleByPowerOfTen
public BigDecimal scaleByPowerOfTen(int n)
Returns a BigDecimal whose numerical value is equal to (this
* 10n). The scale of the result is (this.scale() - n)
.
- Parameters:
-
n
- the exponent power of ten to scale by - Returns:
- a BigDecimal whose numerical value is equal to (
this
* 10n) - Throws:
-
ArithmeticException
- if the scale would be outside the range of a 32-bit integer. - Since:
- 1.5
stripTrailingZeros
public BigDecimal stripTrailingZeros()
Returns a BigDecimal
which is numerically equal to this one but with any trailing zeros removed from the representation. For example, stripping the trailing zeros from the BigDecimal
value 600.0
, which has [BigInteger
, scale
] components equals to [6000, 1], yields 6E2
with [BigInteger
, scale
] components equals to [6, -2]. If this BigDecimal is numerically equal to zero, then BigDecimal.ZERO
is returned.
- Returns:
- a numerically equal
BigDecimal
with any trailing zeros removed. - Since:
- 1.5
compareTo
public int compareTo(BigDecimal val)
Compares this BigDecimal
with the specified BigDecimal
. Two BigDecimal
objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method. This method is provided in preference to individual methods for each of the six boolean comparison operators (<, ==, >, >=, !=, <=). The suggested idiom for performing these comparisons is: (x.compareTo(y)
<op> 0)
, where <op> is one of the six comparison operators.
- Specified by:
-
compareTo
in interfaceComparable<BigDecimal>
- Parameters:
-
val
-BigDecimal
to which thisBigDecimal
is to be compared. - Returns:
- -1, 0, or 1 as this
BigDecimal
is numerically less than, equal to, or greater thanval
.
equals
public boolean equals(Object x)
Compares this BigDecimal
with the specified Object
for equality. Unlike compareTo
, this method considers two BigDecimal
objects equal only if they are equal in value and scale (thus 2.0 is not equal to 2.00 when compared by this method).
- Overrides:
-
equals
in classObject
- Parameters:
-
x
-Object
to which thisBigDecimal
is to be compared. - Returns:
-
true
if and only if the specifiedObject
is aBigDecimal
whose value and scale are equal to thisBigDecimal
's. - See Also:
-
compareTo(java.math.BigDecimal)
,hashCode()
min
public BigDecimal min(BigDecimal val)
Returns the minimum of this BigDecimal
and val
.
- Parameters:
-
val
- value with which the minimum is to be computed. - Returns:
- the
BigDecimal
whose value is the lesser of thisBigDecimal
andval
. If they are equal, as defined by thecompareTo
method,this
is returned. - See Also:
compareTo(java.math.BigDecimal)
max
public BigDecimal max(BigDecimal val)
Returns the maximum of this BigDecimal
and val
.
- Parameters:
-
val
- value with which the maximum is to be computed. - Returns:
- the
BigDecimal
whose value is the greater of thisBigDecimal
andval
. If they are equal, as defined by thecompareTo
method,this
is returned. - See Also:
compareTo(java.math.BigDecimal)
hashCode
public int hashCode()
Returns the hash code for this BigDecimal
. Note that two BigDecimal
objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally not have the same hash code.
- Overrides:
-
hashCode
in classObject
- Returns:
- hash code for this
BigDecimal
. - See Also:
equals(Object)
toString
public String toString()
Returns the string representation of this BigDecimal
, using scientific notation if an exponent is needed.
A standard canonical string form of the BigDecimal
is created as though by the following steps: first, the absolute value of the unscaled value of the BigDecimal
is converted to a string in base ten using the characters '0'
through '9'
with no leading zeros (except if its value is zero, in which case a single '0'
character is used).
Next, an adjusted exponent is calculated; this is the negated scale, plus the number of characters in the converted unscaled value, less one. That is, -scale+(ulength-1)
, where ulength
is the length of the absolute value of the unscaled value in decimal digits (its precision).
If the scale is greater than or equal to zero and the adjusted exponent is greater than or equal to -6
, the number will be converted to a character form without using exponential notation. In this case, if the scale is zero then no decimal point is added and if the scale is positive a decimal point will be inserted with the scale specifying the number of characters to the right of the decimal point. '0'
characters are added to the left of the converted unscaled value as necessary. If no character precedes the decimal point after this insertion then a conventional '0'
character is prefixed.
Otherwise (that is, if the scale is negative, or the adjusted exponent is less than -6
), the number will be converted to a character form using exponential notation. In this case, if the converted BigInteger
has more than one digit a decimal point is inserted after the first digit. An exponent in character form is then suffixed to the converted unscaled value (perhaps with inserted decimal point); this comprises the letter 'E'
followed immediately by the adjusted exponent converted to a character form. The latter is in base ten, using the characters '0'
through '9'
with no leading zeros, and is always prefixed by a sign character '-'
('\u002D'
) if the adjusted exponent is negative, '+'
('\u002B'
) otherwise).
Finally, the entire string is prefixed by a minus sign character '-'
('\u002D'
) if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.
Examples:
For each representation [unscaled value, scale] on the left, the resulting string is shown on the right.
[123,0] "123" [-123,0] "-123" [123,-1] "1.23E+3" [123,-3] "1.23E+5" [123,1] "12.3" [123,5] "0.00123" [123,10] "1.23E-8" [-123,12] "-1.23E-10"Notes:
- There is a one-to-one mapping between the distinguishable
BigDecimal
values and the result of this conversion. That is, every distinguishableBigDecimal
value (unscaled value and scale) has a unique string representation as a result of usingtoString
. If that string representation is converted back to aBigDecimal
using theBigDecimal(String)
constructor, then the original value will be recovered. - The string produced for a given number is always the same; it is not affected by locale. This means that it can be used as a canonical string representation for exchanging decimal data, or as a key for a Hashtable, etc. Locale-sensitive number formatting and parsing is handled by the
NumberFormat
class and its subclasses. - The
toEngineeringString()
method may be used for presenting numbers with exponents in engineering notation, and thesetScale
method may be used for rounding aBigDecimal
so it has a known number of digits after the decimal point. - The digit-to-character mapping provided by
Character.forDigit
is used.
- Overrides:
-
toString
in classObject
- Returns:
- string representation of this
BigDecimal
. - See Also:
-
Character.forDigit(int, int)
,BigDecimal(java.lang.String)
toEngineeringString
public String toEngineeringString()
Returns a string representation of this BigDecimal
, using engineering notation if an exponent is needed.
Returns a string that represents the BigDecimal
as described in the toString()
method, except that if exponential notation is used, the power of ten is adjusted to be a multiple of three (engineering notation) such that the integer part of nonzero values will be in the range 1 through 999. If exponential notation is used for zero values, a decimal point and one or two fractional zero digits are used so that the scale of the zero value is preserved. Note that unlike the output of toString()
, the output of this method is not guaranteed to recover the same [integer, scale] pair of this BigDecimal
if the output string is converting back to a BigDecimal
using the string constructor. The result of this method meets the weaker constraint of always producing a numerically equal result from applying the string constructor to the method's output.
- Returns:
- string representation of this
BigDecimal
, using engineering notation if an exponent is needed. - Since:
- 1.5
toPlainString
public String toPlainString()
Returns a string representation of this BigDecimal
without an exponent field. For values with a positive scale, the number of digits to the right of the decimal point is used to indicate scale. For values with a zero or negative scale, the resulting string is generated as if the value were converted to a numerically equal value with zero scale and as if all the trailing zeros of the zero scale value were present in the result. The entire string is prefixed by a minus sign character '-' ('\u002D'
) if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive. Note that if the result of this method is passed to the string constructor, only the numerical value of this BigDecimal
will necessarily be recovered; the representation of the new BigDecimal
may have a different scale. In particular, if this BigDecimal
has a negative scale, the string resulting from this method will have a scale of zero when processed by the string constructor. (This method behaves analogously to the toString
method in 1.4 and earlier releases.)
- Returns:
- a string representation of this
BigDecimal
without an exponent field. - Since:
- 1.5
- See Also:
-
toString()
,toEngineeringString()
toBigInteger
public BigInteger toBigInteger()
Converts this BigDecimal
to a BigInteger
. This conversion is analogous to the narrowing primitive conversion from double
to long
as defined in The Java™ Language Specification: any fractional part of this BigDecimal
will be discarded. Note that this conversion can lose information about the precision of the BigDecimal
value.
To have an exception thrown if the conversion is inexact (in other words if a nonzero fractional part is discarded), use the toBigIntegerExact()
method.
- Returns:
- this
BigDecimal
converted to aBigInteger
.
toBigIntegerExact
public BigInteger toBigIntegerExact()
Converts this BigDecimal
to a BigInteger
, checking for lost information. An exception is thrown if this BigDecimal
has a nonzero fractional part.
- Returns:
- this
BigDecimal
converted to aBigInteger
. - Throws:
-
ArithmeticException
- ifthis
has a nonzero fractional part. - Since:
- 1.5
longValue
public long longValue()
Converts this BigDecimal
to a long
. This conversion is analogous to the narrowing primitive conversion from double
to short
as defined in The Java™ Language Specification: any fractional part of this BigDecimal
will be discarded, and if the resulting "BigInteger
" is too big to fit in a long
, only the low-order 64 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this BigDecimal
value as well as return a result with the opposite sign.
longValueExact
public long longValueExact()
Converts this BigDecimal
to a long
, checking for lost information. If this BigDecimal
has a nonzero fractional part or is out of the possible range for a long
result then an ArithmeticException
is thrown.
- Returns:
- this
BigDecimal
converted to along
. - Throws:
-
ArithmeticException
- ifthis
has a nonzero fractional part, or will not fit in along
. - Since:
- 1.5
intValue
public int intValue()
Converts this BigDecimal
to an int
. This conversion is analogous to the narrowing primitive conversion from double
to short
as defined in The Java™ Language Specification: any fractional part of this BigDecimal
will be discarded, and if the resulting "BigInteger
" is too big to fit in an int
, only the low-order 32 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this BigDecimal
value as well as return a result with the opposite sign.
intValueExact
public int intValueExact()
Converts this BigDecimal
to an int
, checking for lost information. If this BigDecimal
has a nonzero fractional part or is out of the possible range for an int
result then an ArithmeticException
is thrown.
- Returns:
- this
BigDecimal
converted to anint
. - Throws:
-
ArithmeticException
- ifthis
has a nonzero fractional part, or will not fit in anint
. - Since:
- 1.5
shortValueExact
public short shortValueExact()
Converts this BigDecimal
to a short
, checking for lost information. If this BigDecimal
has a nonzero fractional part or is out of the possible range for a short
result then an ArithmeticException
is thrown.
- Returns:
- this
BigDecimal
converted to ashort
. - Throws:
-
ArithmeticException
- ifthis
has a nonzero fractional part, or will not fit in ashort
. - Since:
- 1.5
byteValueExact
public byte byteValueExact()
Converts this BigDecimal
to a byte
, checking for lost information. If this BigDecimal
has a nonzero fractional part or is out of the possible range for a byte
result then an ArithmeticException
is thrown.
- Returns:
- this
BigDecimal
converted to abyte
. - Throws:
-
ArithmeticException
- ifthis
has a nonzero fractional part, or will not fit in abyte
. - Since:
- 1.5
floatValue
public float floatValue()
Converts this BigDecimal
to a float
. This conversion is similar to the narrowing primitive conversion from double
to float
as defined in The Java™ Language Specification: if this BigDecimal
has too great a magnitude to represent as a float
, it will be converted to Float.NEGATIVE_INFINITY
or Float.POSITIVE_INFINITY
as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the BigDecimal
value.
- Specified by:
-
floatValue
in classNumber
- Returns:
- this
BigDecimal
converted to afloat
.
doubleValue
public double doubleValue()
Converts this BigDecimal
to a double
. This conversion is similar to the narrowing primitive conversion from double
to float
as defined in The Java™ Language Specification: if this BigDecimal
has too great a magnitude represent as a double
, it will be converted to Double.NEGATIVE_INFINITY
or Double.POSITIVE_INFINITY
as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the BigDecimal
value.
- Specified by:
-
doubleValue
in classNumber
- Returns:
- this
BigDecimal
converted to adouble
.
ulp
public BigDecimal ulp()
Returns the size of an ulp, a unit in the last place, of this BigDecimal
. An ulp of a nonzero BigDecimal
value is the positive distance between this value and the BigDecimal
value next larger in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the scale of this
. The result is stored with the same scale as this
so the result for zero and nonzero values is equal to [1,
this.scale()]
.
- Returns:
- the size of an ulp of
this
- Since:
- 1.5