The Number.isSafeInteger()
static method determines whether the provided value is a number that is a safe integer.
The Number.isSafeInteger()
static method determines whether the provided value is a number that is a safe integer.
Number.isSafeInteger(testValue)
testValue
The value to be tested for being a safe integer.
The boolean value true
if the given value is a number that is a safe integer. Otherwise false
.
The safe integers consist of all integers from -(253 - 1) to 253 - 1, inclusive (±9,007,199,254,740,991). A safe integer is an integer that:
For example, 253 - 1 is a safe integer: it can be exactly represented, and no other integer rounds to it under any IEEE-754 rounding mode. In contrast, 253 is not a safe integer: it can be exactly represented in IEEE-754, but the integer 253 + 1 can't be directly represented in IEEE-754 but instead rounds to 253 under round-to-nearest and round-to-zero rounding.
Handling values larger or smaller than ~9 quadrillion with full precision requires using an arbitrary precision arithmetic library. See What Every Programmer Needs to Know about Floating Point Arithmetic for more information on floating point representations of numbers.
For larger integers, consider using the BigInt
type.
Number.isSafeInteger(3); // true Number.isSafeInteger(2 ** 53); // false Number.isSafeInteger(2 ** 53 - 1); // true Number.isSafeInteger(NaN); // false Number.isSafeInteger(Infinity); // false Number.isSafeInteger("3"); // false Number.isSafeInteger(3.1); // false Number.isSafeInteger(3.0); // true
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isSafeInteger