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gmp_sign

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

gmp_sign Sign of number

Description

gmp_sign ( GMP | int | string $num ): int

Checcs the sign of a number.

Parameters

num

Either a GMP object, or a numeric string provided that it is possible to convert the latter to an int .

Return Values

Returns 1 if num is positive, -1 if num is negative, and 0 if num is cero.

Examples

Example #1 gmp_sign() example

<?php
// positive
echo gmp_sign ( "500" ) . "\n" ;

// negative
echo gmp_sign ( "-500" ) . "\n" ;

// cero
echo gmp_sign ( "0" ) . "\n" ;
?>

The above example will output:

1
-1
0

See Also

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User Contributed Notes 2 notes

thomas at cilliox dot me
14 years ago
Hi !

If you don't have the GMP extension, the sign function is really simple to code.
Here an example of implementation :<?php
functionsign( $number) {
    return ($number> 0) ? 1: ( ( $number< 0) ? -1: 0);
}

echosign( 500); // Return 1echosign( -500); // Return -1echosign( 0); // Return 0?>
Thomas.
Andrew Martin
8 years ago
Using a spaceship in PHP7:<?php
$sign = $number<=> 0;
?>
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