Problem:- Write a program to find the factorial number using a while loop
in Java?

Solution:- Let's see 1st what is the factorial number. The multiplication of all integers from 1 to the given number is called a factorial number.

Output:-

Enter a number to find factorial

4

Solution:- Let's see 1st what is the factorial number. The multiplication of all integers from 1 to the given number is called a factorial number.

For example, factorial of 4 is = 4 * 3 * 2 * 1 = 24

Java code:-

Java code:-

```
package com.codeforsolution.java.logical;
import java.util.Scanner;
public class FactorialNumber {
public static void main(String[] args) {
int num;
Scanner s = new Scanner(System.in);
try {
System.out.println("Enter a number to find factorial");
num = s.nextInt();
if (num < 0) {
System.out.println("Factorial not possible for the entered number " + num);
} else {
System.out.println("Factorial of given number is " + findFactorail(num));
}
} catch (Exception e) {
System.out.println("Please enter a valid integer number");
}
s.close();
}
private static int findFactorail(int num) {
int factorial = 1, i = 1;
if (num == 0 || num == 1) {
return factorial;
} else {
while (i <= num) {
factorial = factorial * i;
i++;
}
}
return factorial;
}
}
```

Output:-

Enter a number to find factorial

4

The factorial of given number is 24