Serializable
, Comparable<Boolean>
, Constable
public final class Boolean extends Object implements Serializable, Comparable<Boolean>, Constable
boolean
in an object. An object of type Boolean
contains a single field whose type is boolean
. In addition, this class provides many methods for converting a boolean
to a String
and a String
to a boolean
, as well as other constants and methods useful when dealing with a boolean
.
This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.
Modifier and Type | Field | Description |
---|---|---|
static final Boolean |
FALSE |
The Boolean object corresponding to the primitive value false . |
static final Boolean |
TRUE |
The Boolean object corresponding to the primitive value true . |
static final Class |
TYPE |
The Class object representing the primitive type boolean. |
Constructor | Description |
---|---|
Boolean |
Deprecated, for removal: This API element is subject to removal in a future version. It is rarely appropriate to use this constructor. |
Boolean |
Deprecated, for removal: This API element is subject to removal in a future version. It is rarely appropriate to use this constructor. |
Modifier and Type | Method | Description |
---|---|---|
boolean |
booleanValue() |
Returns the value of this Boolean object as a boolean primitive. |
static int |
compare |
Compares two boolean values. |
int |
compareTo |
Compares this Boolean instance with another. |
Optional |
describeConstable() |
Returns an Optional containing the nominal descriptor for this instance. |
boolean |
equals |
Returns true if and only if the argument is not null and is a Boolean object that represents the same boolean value as this object. |
static boolean |
getBoolean |
Returns true if and only if the system property named by the argument exists and is equal to, ignoring case, the string "true" . |
int |
hashCode() |
Returns a hash code for this Boolean object. |
static int |
hashCode |
Returns a hash code for a boolean value; compatible with Boolean.hashCode() . |
static boolean |
logicalAnd |
Returns the result of applying the logical AND operator to the specified boolean operands. |
static boolean |
logicalOr |
Returns the result of applying the logical OR operator to the specified boolean operands. |
static boolean |
logicalXor |
Returns the result of applying the logical XOR operator to the specified boolean operands. |
static boolean |
parseBoolean |
Parses the string argument as a boolean. |
String |
toString() |
Returns a String object representing this Boolean's value. |
static String |
toString |
Returns a String object representing the specified boolean. |
static Boolean |
valueOf |
Returns a Boolean instance representing the specified boolean value. |
static Boolean |
valueOf |
Returns a Boolean with a value represented by the specified string. |
public static final Boolean TRUE
Boolean
object corresponding to the primitive value true
.public static final Boolean FALSE
Boolean
object corresponding to the primitive value false
.public static final Class<Boolean> TYPE
@Deprecated(since="9", forRemoval=true) public Boolean(boolean value)
valueOf(boolean)
is generally a better choice, as it is likely to yield significantly better space and time performance. Also consider using the final fields TRUE
and FALSE
if possible.Boolean
object representing the value
argument.value
- the value of the Boolean
.@Deprecated(since="9", forRemoval=true) public Boolean(String s)
parseBoolean(String)
to convert a string to a boolean
primitive, or use valueOf(String)
to convert a string to a Boolean
object.Boolean
object representing the value true
if the string argument is not null
and is equal, ignoring case, to the string "true"
. Otherwise, allocates a Boolean
object representing the value false
.s
- the string to be converted to a Boolean
.public static boolean parseBoolean(String s)
boolean
returned represents the value true
if the string argument is not null
and is equal, ignoring case, to the string "true"
. Otherwise, a false value is returned, including for a null argument. Example: Boolean.parseBoolean("True")
returns true
.
Example: Boolean.parseBoolean("yes")
returns false
.
s
- the String
containing the boolean representation to be parsedpublic boolean booleanValue()
Boolean
object as a boolean primitive.boolean
value of this object.public static Boolean valueOf(boolean b)
Boolean
instance representing the specified boolean
value. If the specified boolean
value is true
, this method returns Boolean.TRUE
; if it is false
, this method returns Boolean.FALSE
. If a new Boolean
instance is not required, this method should generally be used in preference to the constructor Boolean(boolean)
, as this method is likely to yield significantly better space and time performance.b
- a boolean value.Boolean
instance representing b
.public static Boolean valueOf(String s)
Boolean
with a value represented by the specified string. The Boolean
returned represents a true value if the string argument is not null
and is equal, ignoring case, to the string "true"
. Otherwise, a false value is returned, including for a null argument.s
- a string.Boolean
value represented by the string.public static String toString(boolean b)
String
object representing the specified boolean. If the specified boolean is true
, then the string "true"
will be returned, otherwise the string "false"
will be returned.b
- the boolean to be convertedboolean
public String toString()
String
object representing this Boolean's value. If this object represents the value true
, a string equal to "true"
is returned. Otherwise, a string equal to "false"
is returned.public int hashCode()
Boolean
object.public static int hashCode(boolean value)
boolean
value; compatible with Boolean.hashCode()
.value
- the value to hashboolean
value.public boolean equals(Object obj)
true
if and only if the argument is not null
and is a Boolean
object that represents the same boolean
value as this object.public static boolean getBoolean(String name)
true
if and only if the system property named by the argument exists and is equal to, ignoring case, the string "true"
. A system property is accessible through getProperty
, a method defined by the System
class. If there is no property with the specified name, or if the specified name is empty or null, then false
is returned.
name
- the system property name.boolean
value of the system property.SecurityException
- for the same reasons as System.getProperty
public int compareTo(Boolean b)
Boolean
instance with another.compareTo
in interface Comparable<Boolean>
b
- the Boolean
instance to be comparedNullPointerException
- if the argument is null
public static int compare(boolean x, boolean y)
boolean
values. The value returned is identical to what would be returned by: Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
x
- the first boolean
to comparey
- the second boolean
to compare0
if x == y
; a value less than 0
if !x && y
; and a value greater than 0
if x && !y
public static boolean logicalAnd(boolean a, boolean b)
boolean
operands.a
- the first operandb
- the second operanda
and b
public static boolean logicalOr(boolean a, boolean b)
boolean
operands.a
- the first operandb
- the second operanda
and b
public static boolean logicalXor(boolean a, boolean b)
boolean
operands.a
- the first operandb
- the second operanda
and b
public Optional<DynamicConstantDesc<Boolean>> describeConstable()
Optional
containing the nominal descriptor for this instance.describeConstable
in interface Constable
Optional
describing the Boolean instance
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Boolean.html