PHP Program to find Factorial of a Number

Posted in PHP Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 131 - Views

⏳ 4 mins

💬 1 Comment

PHP Program to find Factorial of a Number

Photo Credit to CodeToFun

🙋 Introduction

In the world of programming, solving mathematical problems is a fundamental skill. One such mathematical operation is finding the factorial of a number.

The factorial of a non-negative integer is the product of all positive integers less than or equal to that number. It's denoted by the symbol !.

In this tutorial, we'll explore a PHP program to calculate the factorial of a given number.

📄 Example

Let's take a look at the PHP code that achieves this functionality.

calculateFactorial.php

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<?php
// Function to calculate factorial
function calculateFactorial($num)
{
  if ($num == 0 || $num == 1)
  {
    return 1;
  }
  else
  {
    return $num * calculateFactorial($num - 1);
  }
}

// Driver program
// Replace this value with your desired number
$number = 5;

// Call the function to calculate factorial
$result = calculateFactorial($number);

// Display the result
echo "Factorial of $number is: $result\n";

?>

💻 Testing the Program

To test the program with a different number, replace the value of $number in the script.

Output

Factorial of 5 is: 120

Run the script to see the factorial in action.

🧠 How the Program Works

The program defines a function calculateFactorial that recursively calculates the factorial of a given number.
In the script, replace the value of $number with the desired input.
The program then calls the calculateFactorial function to compute the factorial.
The result is displayed using echo.

🧐 Understanding the Concept of Factorial

Before delving into the code, let's take a moment to understand the concept of factorial.

The factorial of a non-negative integer n, denoted as n!, is the product of all positive integers less than or equal to n.

For example, the factorial of 5 (5!) is calculated as 5 × 4 × 3 × 2 × 1 = 120.

🎢 Optimizing the Program

While the provided program is effective, it uses recursion to calculate the factorial. Depending on the input value, this approach may lead to a stack overflow for large numbers. Consider exploring iterative solutions for larger inputs or optimizing the recursive approach.

Feel free to incorporate and modify this code as needed for your specific use case. Happy coding!