isEven

Test if a finite numeric value is an even number.

Usage

var isEven = require( '@stdlib/math/base/assert/is-even' );

isEven( x )

Tests if a finite numeric value is an even number.

var bool = isEven( 5.0 );
// returns false

bool = isEven( -2.0 );
// returns true

bool = isEven( 0.0 );
// returns true

bool = isEven( NaN );
// returns false

Notes

  • The function assumes a finite number. If provided positive or negative infinity, the function will return true, when, in fact, the result is undefined. If x can be infinite, wrap the implementation as follows:

    function check( x ) {
        return (
            x < Infinity &&
            x > -Infinity &&
            isEven( x )
        );
    }
    
    var bool = check( Infinity );
    // returns false
    
    bool = check( -Infinity );
    // returns false
    

Examples

var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var isEven = require( '@stdlib/math/base/assert/is-even' );

var bool;
var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = round( randu()*100.0 );
    bool = isEven( x );
    console.log( '%d is %s', x, ( bool ) ? 'even' : 'not even' );
}