isInteger

Test if a finite double-precision floating-point number is an integer.

Usage

var isInteger = require( '@stdlib/math/base/assert/is-integer' );

isInteger( x )

Tests if a finite double-precision floating-point number is an integer.

var bool = isInteger( 1.0 );
// returns true

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 &&
        isInteger( x )
    );
}

var bool = check( Infinity );
// returns false

bool = check( -Infinity );
// returns false

Examples

var isInteger = require( '@stdlib/math/base/assert/is-integer' );

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

bool = isInteger( 3.14 );
// returns false

bool = isInteger( NaN );
// returns false

C APIs

Usage

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

stdlib_base_is_integer( x )

Tests if a finite double-precision floating-point number is an integer.

bool out = stdlib_base_is_integer( 1.0 );
// returns true

out = stdlib_base_is_integer( 3.14 );
// returns false

The function accepts the following arguments:

x: [in] double input value.

bool stdlib_base_is_integer( const double x );

Examples

#include "stdlib/math/base/assert/is_integer.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 ) - 50.0;
        v = stdlib_base_is_integer( x );
        printf( "x = %lf, is_integer(x) = %s\n", x, ( v ) ? "true" : "false" );
    }
}