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JavaScript Number.isSafeInteger() Method

JavaScript Number Object

Example

Check if the parameter is a "safe integer":


Definition and Usage

The isSafeInteger() method determines whether the provided value is a "safe integer" (safe integer). It returns true if the value is a safe integer, otherwise it returns false.

A safe integer is an integer that:

For example, 2^53 - 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, 2^53 is not a safe integer. It can be represented using IEEE-754, but 2^53 + 1 cannot be directly represented and is rounded to 2^53 in round-to-nearest and toward-zero rounding modes.

The range of safe integers is from -(2^53 - 1) to 2^53 - 1, inclusive.

Number.isSafeInteger(3);                    // true
Number.isSafeInteger(Math.pow(2, 53))       // false
Number.isSafeInteger(Math.pow(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

Browser Support

Number.isSafeInteger() is a feature of ECMAScript6 (ES6).

Most modern browsers support ES6 (JavaScript 2015).

Number.isSafeInteger() is not supported in Internet Explorer 11 and earlier versions.

Chrome Edge Firefox Safari Opera
Yes Yes Yes Yes Yes

Syntax

Number.isSafeInteger(value)

Parameter Values

Parameter Description
value The value to be tested.

Return Value

Type Description
Boolean Returns true if the value is a safe integer, otherwise returns false.

Technical Details

| JavaScript Version: | ECMAScript 6 | | --- | --- |


More Examples

Example

Check if the parameter is a safe integer:

JavaScript Number Object

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