Factorial of a number is calculated by multiplying it with all the numbers below it starting from 1. For example factorial of 4 is 4*3*2*1.
Factorial of 0 (zero) is always 1
Factorial of a negative number doesn’t exist.
In this post I will show you how to create a Factorial program in Java using recursion and without using recursion.
In this blog, we are going to learn how to create a factorial program in Java.
What is a Factorial Program?
A factorial number is a product of all positive descending integers. For example, the factorial of 6 (denoted as 6!) is 1*2*3*4*5*6 = 720. And the factorial of 3 (denoted as 3!) is 1*2*3 = 6. The factorial of 0! is 1.
We can create a function to calculate the factorial program in Java. It is given below:
public class FactorialProgram {
public static void main(String[] args) {
int n = 5; //Initialize a number, here it is 5
int result = 1; //Initialize a result to hold the factorial value later on
for(int i=1; i<=n; i++) { //Loop through each number from 1 to n, i.e. from 1 to 5 in this case
result = result * i; //Multiply each number with the previous result value, i.e. result = 1*1, then result = 2*1, then result = 6*
This tutorial will show you how to write a factorial program in Java. It is an example of a recursive function as it calls itself during its execution.
First, let's define what a factorial is! The mathematical definition is:
n! = n × (n-1) × (n-2) ×……× 3 × 2 × 1
So, 3! = 3 x 2 x 1 = 6 and 5! = 5 x 4 x 3 x 2 x 1 = 120.
You can see that the value increases quite rapidly as the number gets bigger!
Now, let's look at an example of how to write a factorial program in Java.
import java.util.Scanner;
public class Factorial {
public static void main(String[] args) {
Scanner reader = new Scanner(System.in);
int fact = 1, n;
System.out.println("Enter a number: ");
n = reader.nextInt();
for (int i = 1; i<=n; i++) {
fact *= i;
}
System.out.println("Factorial of " + n + " is: " + fact);
}
}
import java.util.Scanner;
public class Factorial
{
public static void main(String args[]){
int i,n,fact=1;
System.out.println("Enter the number");
Scanner sc=new Scanner(System.in);
n=sc.nextInt();
for(i=1;i<=n;i++)
fact=fact*i;
System.out.println("Factorial is"+fact);
}
}
public class Factorial {
public static void main(String[] args) {
// TODO Auto-generated method stub
int result=1;
int number=5;
for(int i=1;i<=number;i++) {
result=result*i;}
System.out.println("Factorial of a number is "+result);
}
}
import java.util.*;
public class MyClass {
public static void main(String args[]) {
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int f=1;
for(int i=1;i<=n;i++)
f*=i;
System.out.println(f);
}
}