(PHP 4 >= 4.0.4, PHP 5, PHP 7)
gmp_clrbit — Clear bit
Clears (sets to 0) bit index in
a. The index starts at 0.
a可以是一个 GMP 数据 resouce，或一个可以转换为数值的字符串。
indexThe index of the bit to clear. Index 0 represents the least significant bit.
GMP 数值资源.
Example #1 gmp_clrbit() example
<?php
$a = gmp_init("0xff");
gmp_clrbit($a, 0); // index starts at 0, least significant bit
echo gmp_strval($a) . "\n";
?>
以上例程会输出：
254
Note:
Unlike most of the other GMP functions, gmp_clrbit() must be called with a GMP resource that already exists (using gmp_init() for example). One will not be automatically created.