## Q. PHP program to swap two numbers without using temporary variable.

Here you will find an algorithm and program in PHP to swap 2 numbers without using any third or temporary variable.

Swapping two number : Swap two numbers means exchange the values of two variables with each other. Suppose we are given 2 numbers num1 = 10 and num2 = 20 and we have to swap these 2 numbers without using third variable. After swaping value of num1 = 20 and num2 = 10.

## Algorithm to swap two numbers without using third variable

```START
Step 1 ->  Take two integer as input num1 and num2.
Step 2 ->  Print number before swapping
Step 3 ->  num1 = num1 + num2;
Step 4 ->  num2 = num1 - num2;
Step 5 ->  num1 = num1 - num2;
Step 6 ->  Print numbers after swapping
STOP
```

# PHP Program to Swap Two Numbers Without Using Temporary Variable

```<?php
\$num1=10;
\$num2=20;
echo "Number before swapping is \$num1 and \$num2 \n";
\$num1=\$num1+\$num2;
\$num2=\$num1-\$num2;
\$num1=\$num1-\$num2;
echo "Number after swapping is \$num1 and \$num2";
?>
```

#### Output

```Enter Two Numbers :
10 20
Number before swapping is 10 and 20
Number after swapping is 20 and 10
```