gmp_scan1

(PHP 4 >= 4.0.4, PHP 5)

gmp_scan1 -- Scan for 1

Description

int gmp_scan1 ( resource a, int start )

Scans a , starting with bit start , towards more significant bits, until the first set bit is found. Returns the index of the found bit. If no set bit is found, -1 is returned.

例子 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" ;
?>

The printout of the above program will be:

3
9