gmp_sign

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

gmp_sign — Sign of number

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

Checks the sign of a number.

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

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

示例 #1 gmp_sign() example

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

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

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

以上示例会输出：

1
-1
0