Add Two Numbers Without using Arithmetic Operators in PHP

This article will show you how to add two numbers without using Arithmetic operators in PHP. There are two methods to add two numbers, these are:

Using Bitwise Operators

We will use Bitwise Operator to add two numbers. First, we check num2 is not equal to zero, then Calculate the carry using & operator, and then use XOR operator to get sum of numbers, At last, shift the carry to 1 left.

PHP

<?php

function addNum($num1, $num2) {
    while ($num2 != 0) {

        // Calculate the carry
        $carry = $num1 & $num2;

        // XOR to get the sum
        $num1 = $num1 ^ $num2;

        // Shift the carry to the left
        $num2 = $carry << 1;
    }

    return $num1;
}

// Driver Code
$num1 = 5;
$num2 = 7;

echo "Sum : " . addNum($num1, $num2);

?>

Output

Sum : 12

Using Recursion

In this section, we will use the above approach with Recursion to calculate the sum of two numbers.

Example:

PHP

<?php

function addNum($num1, $num2) {
    if ($num2 == 0) {
        return $num1;
    } else {
        return addNum($num1 ^ $num2, ($num1 & $num2) << 1);
    }
}

// Driver Code
$num1 = 5;
$num2 = 7;

echo "Sum : " . addNum($num1, $num2);

?>

Output

Sum : 12