# @stdlib/math-base-assert-is-even

0.2.2 • Public • Published

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

# isEven

Test if a finite numeric value is an even number.

## Installation

npm install @stdlib/math-base-assert-is-even

## 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' );
}

## C APIs

### Usage

#include "stdlib/math/base/assert/is_even.h"

#### stdlib_base_is_even( x )

Tests if a finite numeric value is an even number.

bool out = stdlib_base_is_even( 1.0 );
// returns false

out = stdlib_base_is_even( 4.0 );
// returns true

The function accepts the following arguments:

• x: [in] double input value.
bool stdlib_base_is_even( const double x );

### Examples

#include "stdlib/math/base/assert/is_even.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

int main( void ) {
double x;
bool v;
int i;

for ( i = 0; i < 100; i++ ) {
x = ( ( (double)rand() / (double)RAND_MAX ) * 100.0 );
v = stdlib_base_is_even( x );
printf( "x = %lf, is_even(x) = %s\n", x, ( v ) ? "even" : "not even" );
}
}

## 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.

## Package Sidebar

### Install

npm i @stdlib/math-base-assert-is-even

### Repository

github.com/stdlib-js/math-base-assert-is-even

stdlib.io

73,724

0.2.2

Apache-2.0

33.7 kB

16