PHP Manual: Scan for 0

Description

int gmp_scan0(GMPintstring $num1, int $start)

Scans num1, starting with bit start, towards more significant bits, until the first clear bit is found.

Parameters

num1

The number to scan.

A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init with automatic base detection (i.e. when base is equal to 0).

start

The starting bit.

Return Values

Returns the index of the found bit, as an int. The index starts from 0.

Examples

Example #1 gmp_scan0 example

<?php
// "0" bit is found at position 3. index starts at 0
$s1 = gmp_init("10111", 2);
echo gmp_scan0($s1, 0) . "\n";

// "0" bit is found at position 7. index starts at 5
$s2 = gmp_init("101110000", 2);
echo gmp_scan0($s2, 5) . "\n";
?>

The above example will output:

3
7