Test if a finite numeric value is an even number.
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> Test if a finite numeric value is an even number.
``bash`
npm install @stdlib/math-base-assert-is-even
`javascript`
var isEven = require( '@stdlib/math-base-assert-is-even' );
#### isEven( x )
Tests if a finite numeric value is an even number.
`javascript
var bool = isEven( 5.0 );
// returns false
bool = isEven( -2.0 );
// returns true
bool = isEven( 0.0 );
// returns true
bool = isEven( NaN );
// returns false
`
- 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:
`javascript
function check( x ) {
return (
x < Infinity &&
x > -Infinity &&
isEven( x )
);
}
var bool = check( Infinity );
// returns false
bool = check( -Infinity );
// returns false
`
`javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var isEven = require( '@stdlib/math-base-assert-is-even' );
var opts = {
'dtype': 'float64'
};
var x = discreteUniform( 100, 0, 100, opts );
function isEvenWrapper( integer ) {
return ( isEven( integer ) ) ? 'even' : 'not even';
}
logEachMap( '%d is %s', x, isEvenWrapper );
`
*
`c`
#include "stdlib/math/base/assert/is_even.h"
#### stdlib_base_is_even( x )
Tests if a finite numeric value is an even number.
`c
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.
`c`
bool stdlib_base_is_even( const double x );
`c
#include "stdlib/math/base/assert/is_even.h"
#include
#include
#include
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" );
}
}
`
*
- [@stdlib/math-base/assert/is-odd][@stdlib/math/base/assert/is-odd]: test if a finite numeric value is an odd number.
*
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
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---
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