The gmp_testbit() is an in-built function in PHP which checks if the specified bit of a given GMP number(GNU Multiple Precision: For large numbers) is set or not.
Syntax:
gmp_testbit($num, $index)
Parameters: The function accepts two parameters which are mandatory and are described below:
- $num – The This function accepts one GMP number $num whose specified bit is to be checked.This parameter can be a GMP object in PHP version 5.6 and later, or we are also allowed to pass a numeric string provided that it is possible to convert that string to a number.
- $index- The specified index whose bit in $num is to be checked. It is an integer.
Return Value: The function returns true if the specified $index bit is set, otherwise it returns false if the bit is not set.
Examples:
Input : $num=4 $index=2 Output : true Input : $num=9 $index=2 Output : false
Below programs illustrate the use of gmp_testbit() function:
Program 1: The program below demonstrates the working of gmp_testbit() function when GMP number is passed as an argument.
<?php // PHP program to check the sign // of a number // numeric string arguments $num = gmp_init("1001", 2); $index1 = 2; $index2 = 0; // checks if the 2nd index bit in 9 (1001) is set or not var_dump(gmp_testbit($num, $index1))."\n"; // checks if the 0th index bit in 9 (1001) is set or not var_dump(gmp_testbit($num, $index2)); ?> |
Output:
bool(false) bool(true)
Program 2: The program below demonstrates the working of gmp_testbit() when numeric string is passed as an argument.
<?php // PHP program to check the sign // of a number // numeric string arguments $num = "9"; $index1 = 2; $index2 = 3; // checks if the 2nd index bit in 9 (1001) // is set or not var_dump(gmp_testbit($num, $index1))."\n"; // checks if the 3rd index bit in 9 (1001) // is set or not var_dump(gmp_testbit($num, $index2)); ?> |
Output:
bool(false) bool(true)
Reference: http://php.net/manual/en/function.gmp-testbit.php
