Factorial of n is the product of all positive descending integers. Factorial of n is denoted by n!. For example:
4! = 4*3*2*1 = 24 5! = 5*4*3*2*1 = 120
Factorial Program using while loop
public class FactorialProgram { public static void main(String[] args) { int factNumber = 4; int total = 1; int n = 1; while (n <= factNumber) { total = total * n; n = n + 1; } System.out.println("Factorial of " + factNumber + " is " + total); } }
Output
Factorial of 4 is 24
Factorial Program using For loop
public class FactorialProgram { public static void main(String[] args) { int factNumber = 5; int total = 1; for (int n = 1; n <= factNumber; n++) { total = total * n; } System.out.println("Factorial of " + factNumber + " is " + total); } }
Output
Factorial of 5 is 120
Factorial Program using recursion
class FactorialProgram { public static int factorial(int n) { if (n == 0) { return 1; } else { return (n * factorial(n - 1)); } } public static void main(String args[]) { int total = 1; int factNumber = 5; total = factorial(factNumber); System.out.println("Factorial of " + factNumber + " is " + total); } }
Output
Factorial of 5 is 120