The gmp_root() is an in-built function in PHP which returns the integer part of the N-th root of a GMP number(GNU Multiple Precision: For large numbers).
Syntax:
gmp_root( $num, $n )
Parameters: The function accepts two mandatory parameters $num and $n.
- $num – This is the GMP number whose integer part of the n-th root is returned. The parameter is 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.
- $n – the positive n-th root of the number. It is an integer value.
Return Value: This function returns a positive GMP number which is the integer part of the N-th root of the $num.
Examples:
Input : $num = "20" $n = 2 Output : 4 Input : $num = "9" $n = 2 Output : 2
Below programs illustrate the gmp_root() function:
Program 1: The program below demonstrates the working of gmp_root() function when GMP number is passed as argument..
php
<?php// PHP program to calculate the // integer part of N-th root of // a GMP number // GMP number as arguments $num = gmp_init("1001", 2); $n = 3;// function calculates the pow raised to // number modulo mod // integer part of cubic root of 9$root = gmp_root($num, $n); // gmp_strval Convert GMP number to string // representation in given base(default 10).echo gmp_strval($root, 2);?> |
Output:
10
Program 2: The program below demonstrates the working of gmp_root() when numeric string is passed as an argument.
php
<?php// PHP program to calculate the // integer part of N-th root of // a GMP number // GMP number as arguments $num = "9"; $n = 3;// function calculates the pow raised to // number modulo mod // integer part of cubic root of 9$root = gmp_root($num, $n); echo $root;?> |
Output:
2
Program 3: Program to find the integer part of a square root of a number.
php
<?php// PHP program to calculate the // integer part of N-th root of // a GMP number // GMP number as arguments $num = "25"; $n = 2;// function calculates the pow raised to // number modulo mod // integer part of square root of 25$root = gmp_root($num, $n); echo $root;?> |
Output:
5
Reference:
http://php.net/manual/en/function.gmp-root.php
