# 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
```

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