Java Recursive Method: Calculate the factorial of a number

Java Recursive: Exercise-1 with Solution

Write a Java recursive method to calculate the factorial of a given positive integer.

Sample Solution:

Java Code:

public class FactorialCalculator {

  public static int calculateFactorial(int n) {
    // Base case: factorial of 0 is 1
    if (n == 0) {
      return 1;
    }

    // Recursive case: multiply n with factorial of (n-1)
    return n * calculateFactorial(n - 1);
  }

  public static void main(String[] args) {
    int number = 7;
    int factorial = calculateFactorial(number);
    System.out.println("Factorial of " + number + " is: " + factorial);
    number = 12;
    factorial = calculateFactorial(number);
    System.out.println("\nFactorial of " + number + " is: " + factorial);
  }
}

Sample Output:

Factorial of 7 is: 5040

Factorial of 12 is: 479001600

Explanation:

In the above exercises -

First, we define a class "FactorialCalculator" that includes a recursive method calculateFactorial() to calculate the factorial of a given positive integer n.

The calculateFactorial() method follows the recursive factorial definition. It has two cases:

• Base case: If n is 0, it returns 1. This is the termination condition for recursion.
• Recursive case: For any positive n, it multiplies n with the factorial of n-1. This step is repeated recursively until n reaches 0.

In the main() method, we demonstrate the calculateFactorial() method by calculating the factorial of 7 and 12.

Flowchart:

Java Code Editor:

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