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This document uses PHP Chinese website manual Release
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
gmp_scan1 — Scan for 1
$a
, int $start
)
Scans a
, starting with bit
start
, towards more significant bits,
until the first set bit is found.
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.
Returns the index of the found bit, as an integer . If no set bit is found, -1 is returned.
Example #1 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