# PHP Program to find Factorial of a Number

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## What is Factorial of a Number?

The factorial of a number n can be defined as the product of all positive numbers less than or equal to n. For example, the factorial of 6 is 1 × 2 × 3 × 4 × 5 × 6 = 720.

## Examples

The following table provides few examples of factorial of a number.

NumberFactorialResult
1!11
2!1 × 22
3!1 × 2 × 36
4!1 × 2 × 3 × 424

Note: In Mathematics, factorial of a number is represented by exclamation mark.

Tips: It is recommended to use our online Factorial of a Number calculator for better understanding.

## Find a Factorial of a Number

In the following example, we will find a factorial of a number 6.

### Example

PHP Compiler
<?php \$num = 6; \$i = 1; \$factorial = 1; for(\$i=1; \$i<=\$num; \$i++) \$factorial *= \$i; if(\$num) echo "Factorial of \$num: \$factorial"; else echo "Factorial of 0 is 0"; ?>

### Output

Factorial of 6: 720

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