(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
gmp_neg — Negate number
gmp_neg(GMP|int|string $num): GMP
Returns the negative value of a number.
num A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init() with automatic base detection (i.e. when base is equal to 0).
Returns -num, as a GMP number.
Example #1 gmp_neg() example
<?php
$neg1 = gmp_neg("1");
echo gmp_strval($neg1) . "\n";
$neg2 = gmp_neg("-1");
echo gmp_strval($neg2) . "\n";
?> The above example will output:
-1 1
© 1997–2025 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.gmp-neg.php