This java program finds factorial of a number. Entered number is checked first if its negative then an error message is printed.
Java Source Code
import java.util.Scanner; class Factorial { public static void main(String args[]) { int n, c, fact = 1; System.out.println("Enter an integer to calculate it's factorial"); Scanner in = new Scanner(System.in); n = in.nextInt(); if ( n < 0 ) System.out.println("Number should be non-negative."); else { for ( c = 1 ; c <= n ; c++ ) fact = fact*c; System.out.println("Factorial of "+n+" is = "+fact); } } }
Output
You can also find factorial using recursion, in the code fact is an integer variable so only factorial of small numbers will be correctly displayed or which fits in 4 bytes. For large numbers you can use long data type.