PHP Program - Power of a Number

If power (or exponential) of number indicates how many the number is multiplied by itself to get the final number. For example:

x raised to the power 2 = x² = x*x

x raised to the power 3 = x³ = x*x*x

Method 1: Using conditional statement

In the example below, a function called Power() is created to calculate power of a number. It uses while loop to achieve this. This method can be used to calculate the power of a number where power should be a non-negative integer.

<?php
function Power($x, $n) {
  $finalnum = 1;
  $n1 = $n;
  while($n1 > 0){
    $finalnum = $finalnum * $x;
    $n1--;
  }
  echo "$x raised to the power $n = $finalnum \n";
}

Power(3, 5);
Power(5, 0);
Power(6, 2);
?>

The above code will give the following output:

3 raised to the power 5 = 243
5 raised to the power 0 = 1
6 raised to the power 2 = 36

Method 2: Using pow() function of PHP

The pow() function of PHP <cmath> header file can also be used to calculate power of a number. It can be used to calculate xⁿ for any value of n (n can be negative or fraction).

<?php
$x = 3; $y = 5; $z = 6;
$a = 5; $b = 0; $c = 2;

echo "$x raised to the power $a = ".pow($x, $a)."\n";
echo "$y raised to the power $b = ".pow($y, $b)."\n";
echo "$z raised to the power $c = ".pow($z, $c)."\n";
?>

The above code will give the following output:

3 raised to the power 5 = 243
5 raised to the power 0 = 1
6 raised to the power 2 = 36