gmp_scan1()
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
Scan for 1
说明
gmp_scan1(GMP$a,int $start): int
Scans$a, starting with bit$start, towards more significant bits, until the first set bit is found.
参数
- $a
The number to scan.
可以是一个 GMP数据resouce,或一个可以转换为数值的字符串。
- $start
The starting bit.
返回值
Returns the index of the found bit, as an integer. If no set bit is found,-1 is returned.
范例
gmp_scan1() example
<?php // "1" bit is found at position 3. index starts at 0 $s1 = gmp_init("01000", 2); echo gmp_scan1($s1, 0) . "\n"; // "1" bit is found at position 9. index starts at 5 $s2 = gmp_init("01000001111", 2); echo gmp_scan1($s2, 5) . "\n"; ?>
以上例程会输出:
3 9