@stdlib/assert-is-safe-integer NPM

isSafeInteger

Test if a value is a number having a safe integer value.

Installation

npm install @stdlib/assert-is-safe-integer

Usage

var isSafeInteger = require( '@stdlib/assert-is-safe-integer' );

isSafeInteger( value )

Tests if a value is a number having a safe integer value.

var Number = require( '@stdlib/number-ctor' );

var bool = isSafeInteger( 5.0 );
// returns true

bool = isSafeInteger( new Number( 5.0 ) );
// returns true

bool = isSafeInteger( 2.0e200 );
// returns false

bool = isSafeInteger( -3.14 );
// returns false

bool = isSafeInteger( null );
// returns false

isSafeInteger.isPrimitive( value )

Tests if a value is a primitive number having a safe integer value.

var Number = require( '@stdlib/number-ctor' );

var bool = isSafeInteger.isPrimitive( -3.0 );
// returns true

bool = isSafeInteger.isPrimitive( new Number( -3.0 ) );
// returns false

isSafeInteger.isObject( value )

Tests if a value is a Number object having a safe integer value.

var Number = require( '@stdlib/number-ctor' );

var bool = isSafeInteger.isObject( 3.0 );
// returns false

bool = isSafeInteger.isObject( new Number( 3.0 ) );
// returns true

Notes

An integer valued number is "safe" when the number can be exactly represented as a double-precision floating-point number. For example,
```
var MAX_SAFE_INTEGER = require( '@stdlib/constants-float64-max-safe-integer' );
// returns 9007199254740991

var x = 9007199254740992;
// returns 9007199254740992

var y = 9007199254740993;
// returns 9007199254740992

var bool = ( x === y );
// returns true
```
In this example, x and y should be distinct, but they are not due to constraints imposed by storing numeric values in double-precision floating-point format. "Safe" integers are thus double-precision floating-point numbers having integer values with unequivocal binary representations.

Examples

var Number = require( '@stdlib/number-ctor' );
var isSafeInteger = require( '@stdlib/assert-is-safe-integer' );

var bool = isSafeInteger( -5.0 );
// returns true

bool = isSafeInteger( 0.0 );
// returns true

bool = isSafeInteger( new Number( 5.0 ) );
// returns true

bool = isSafeInteger( 2.0e200 );
// returns false

bool = isSafeInteger( 5.256 );
// returns false

bool = isSafeInteger( 1.0/0.0 );
// returns false

bool = isSafeInteger( -1.0/0.0 );
// returns false

bool = isSafeInteger( NaN );
// returns false

bool = isSafeInteger( '5' );
// returns false

bool = isSafeInteger( null );
// returns false

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.