Php/docs/function.gmp-scan1

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gmp_scan1

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

gmp_scan1Scan for 1


Description

gmp_scan1 ( GMP $a , int $start ) : int

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


Parameters

a

The number to scan.

Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and later, or a numeric string provided that it is possible to convert the latter to a number.

start

The starting bit.


Return Values

Returns the index of the found bit, as an int. If no set bit is found, -1 is returned.


Examples

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";?>

The above example will output:


3
9