(PHP 4 >= 4.0.4, PHP 5)
gmp_abs — Absolute value
Get the absolute value of a number.
It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.
Returns the absolute value of a , as a GMP number.
Example #1 gmp_abs() example
<?php
$abs1 = gmp_abs("274982683358");
$abs2 = gmp_abs("-274982683358");
echo gmp_strval($abs1) . "\n";
echo gmp_strval($abs2) . "\n";
?>
上例将输出：
274982683358 274982683358