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Hi I am stuck. Please help me

macca Mason

Joined: Nov 26, 2003
Posts: 13
Hi I need a program which should calculate the factorial of given number. (the number is entered by the user)
(the factorial of 4 for example is 4*3*2*1 answer is 24)
My question is "how do I calculate the factorial of a given number?"

Can you please help me? I have stick on this for some time.
(btw I am new to programming)

class Conpronum
public static void main(String[ ]args)
//Declare variables
int num1

//Read in the user number
System.out.println ("\nPlease enter your a whole number:");
num1 = EasyIn.getInt();

This is all I have done so far. I don't know how to tackle this problem.
Ernest Friedman-Hill
author and iconoclast

Joined: Jul 08, 2003
Posts: 24199

Let's say your number is N.
You must use a loop. Before the loop, set a variable "f" to 1, and another variable "n" to N. Then, each time through the loop, multiply f by n, then subtract 1 from n. When n gets to be 1, you're done, and you can exit the loop, and "f" holds the answer.

[Jess in Action][AskingGoodQuestions]
Elouise Kivineva
Ranch Hand

Joined: Feb 07, 2002
Posts: 154
About the recursive method (beautifully simple but a little tough for a beginner to understand):
About the iterative method:
Get the number.
To begin, set the factorial of the number to be one.
(Create an int named "factorial")
While the number is greater than one
Set the factorial to be the factorial multiplied by the number.
Decrement the number.
Print out the factorial
macca Mason

Joined: Nov 26, 2003
Posts: 13
Thx alot Ernest.
I will try and make these changes. But I new to programming so if I get stuck again trying to make these changes I will post here.
macca Mason

Joined: Nov 26, 2003
Posts: 13
Thx Elouise
I will try my best to follow this.
I agree. Here's the link:
subject: Hi I am stuck. Please help me
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