JavaScript Number isSafeInteger()

Are these safe integers?

Number.isSafeInteger(123);
Number.isSafeInteger(-123);
Number.isSafeInteger('123');

Number.isSafeInteger(5-2);
Number.isSafeInteger(0);
Number.isSafeInteger(0.5);
Number.isSafeInteger(0/0);

Description

The Number.isSafeInteger() method returns trueif a number is a safe integer.

Otherwise it returns false.

A safe integer is an integer that can be exactly represented as an IEEE-754 double precision number: all integers from (2⁵³ - 1) to -(2⁵³ - 1).

Number.isSafeInteger( value)

Parameter	Description
value	Required. The value to be tested.

Type	Description
A boolean	`true` if the value is a safe integer, otherwise `false`.

Are these safe integers?

Number.isSafeInteger(Math.pow(2, 53));
Number.isSafeInteger(Math.pow(2, 53) - 1);

Number.isSafeInteger(true);
Number.isSafeInteger(false);
Number.isSafeInteger(Infinity);
Number.isSafeInteger(-Infinity);

Number.isSafeInteger() is an ECMAScript6 (ES6) feature.

ES6 (JavaScript 2015) is supported in all modern browsers:


Chrome	Edge	Firefox	Safari	Opera
Yes	Yes	Yes	Yes	Yes

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