PHP | gmp_sub() Function

The gmp_sub() is an in-built function in PHP which returns the subtraction of the two GMP numbers.(GNU Multiple Precision: For large numbers)

Syntax:

gmp_sub($num1, $num2)

Parameters: This function accepts two GMP numbers $num1 and $num2 as mandatory parameters shown in the above syntax. These parameters 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.

Return Value: The function returns the subtraction of two numbers $num1 and $num2.

Examples:

Input : $num1=5 , $num2=10
Output : -5 

Input : $num1=7 , $num2=1
Output : 6 

Below programs illustrate the gmp_sub() function:

Program 1: The program below demonstrates the working of gmp_sub() function when GMP number are passed as arguments.

<?php
// PHP program to subtract two
// two numbers

// GMP number as arguments
$num1 = gmp_init("101", 2);
$num2 = gmp_init("1010", 2);

// 5-10 = -5
$sub = gmp_sub($num1, $num2);

// gmp_strval converts GMP number to string
// representation in given base(default 10).
echo gmp_strval($sub, 2);
?>

Output:

-101

Program 2: The program below demonstrates the working of gmp_sub() when numeric string are passed as arguments.

<?php
// PHP program to subtract two
// two numbers

// numeric strings number as arguments
$num1 = "7";
$num2 = "1";

// 7-1 = 6
$sub = gmp_sub($num1, $num2);

echo $sub;
?>

Output:

6

Reference:
http://php.net/manual/en/function.gmp-sub.php