Coding issue

Ok I need to code a program that uses arithmetic operations to reverse an integer input by the user and display it to them.

Eg. 1234 needs to be output back to the user as 4321.

So I use the modular operation to get each digit:
1234 % 10 = 4
123 & 10 = 3
12 % 10 = 2
1 % 10 = 1

So I have the pattern 4,3,2,1. Without predefining a set number of digits for a user to enter, and without using loops, how would I display the number 4321 back to the user?

For example, I'd need to keep doing the modular of the function until the remainder is 0, but we aren't allowed to use loops. We also can't use any predefined java classes (like stringbuffer's .reverse()). Can anyone suggest some code?

Jimmy suggested using bit shifts but I can't understand it all that well and neither does he.

 

How in fuck are you supposed to do it without a loop? >_>. I can't think of any way to do it without a loop.

Do you have to use the remainder to make it go backwards?

 

Jesus.

Read. Understand. Use. >_>.

 

I tried to understand. When I tried to use it it was bad.

I don't know how I'm supposed to do it without a loop...

and yeah the remainder is the number backwards.

 

Code:

    private static int reverse(int i)
    {
	int returnVal = 0;

	returnVal += ((i / 1) % 10) * 100000000;
	returnVal += ((i / 10) % 10) * 10000000;
	returnVal += ((i / 100) % 10) * 1000000;
	returnVal += ((i / 1000) % 10) * 100000;
	returnVal += ((i / 10000) % 10) * 10000;
	returnVal += ((i / 100000) % 10) * 1000;
	returnVal += ((i / 1000000) % 10) * 100;
	returnVal += ((i / 10000000) % 10) * 10;
	returnVal += ((i / 100000000) % 10) * 1;

	return returnVal;
    }

The above works, but looks like shit. The problem it has, though, is that it adds trailing zeros (123456 [AKA 000123456] becomes 654321000). It would be perfect if you made a method to remove the trailing zeros (normally I would, but I'm a bit strapped for time atm, will probably make that method when I get home from school).

 

Wait. Dur. Ints have a max number they can be... Forgot about that. Good job Jimmmy.

But. You fail. Read your post. >_<.

 

Oops.

Wrote another shitty method to remove the trailing zeros from an int. Should be fully working, now.
http://pastebin.com/cctmDE4Z