gmp_setbit
(PHP 4 >= 4.0.4, PHP 5)
gmp_setbit — Set bit
说明
void gmp_setbit ( resource $a , int $index [, bool $set_clear = true ] )Sets bit index in a.
参数
- a
-
The number being set to.
可以是一个 GMP 数据 resouce，或一个可以转换为数值的字符串。
- index
-
The set bit.
- set_clear
-
Defines if the bit is set to 0 or 1. By default the bit is set to 1. Index starts at 0.
返回值
GMP 数值资源.
范例
Example #1 gmp_setbit() example 以上例程会输出：
<?php
$a = gmp_init("0xfd");
gmp_setbit($a, 1); // index starts at 0
echo gmp_strval($a) . "
";
?>
255
注释
Note:
Unlike most of the other GMP functions, gmp_setbit() must be called with a GMP resource that already exists (using gmp_init() for example). One will not be automatically created.
参见
- gmp_clrbit() - Clear bit
- gmp_testbit() - Tests if a bit is set
