Write a Java Program to Find Factorial of a Number Using Recursion

In Java programming, recursion is a technique that allows a function to call itself during its execution.

Recursion is commonly used to solve problems that can be broken down into smaller, simpler problems.

One common problem that can be solved using recursion is to find the factorial of a number.

In this tutorial, we will discuss how to find the factorial of a number using recursion in Java.

Factorial of a number n is the product of all positive integers less than or equal to n.

It is denoted by n!. For example, the factorial of 5 is 5! = 5 × 4 × 3 × 2 × 1 = 120.

To find the factorial of a number using recursion, we can define a recursive function that calls itself with a smaller value until it reaches the base case, which is the factorial of 1.

Here is the Java code to find the factorial of a number using recursion:

public class FactorialUsingRecursion {
    public static void main(String[] args) {
        int num = 5;
        int factorial = factorial(num);
        System.out.println("Factorial of " + num + " is " + factorial);
    }

    public static int factorial(int n) {
        if (n == 1) {
            return 1;
        } else {
            return n * factorial(n - 1);
        }
    }
}

In this code, we define a function called factorial that takes an integer n as input and returns its factorial.

The function checks if n is equal to 1, which is the base case.

If it is, the function returns 1.

If not, the function calls itself with n-1 and multiplies the result with n to get the factorial of n.

In the main function, we call the factorial function with the input value num (which is set to 5) and store the result in the factorial variable.

Finally, we print the result using the System.out.println function.

When you run this program, it will output the following: