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Thread: help with number game using nested for and doWhile loop

  1. #1
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    Default help with number game using nested for and doWhile loop

    Trying to create a game that returns the amount of times it takes the all numbers between a beginning input and ending input to work through a loop before it becomes zero. Any ideas on why I keep getting an infinite loop?

     
    import java.util.Scanner;
     
    class Suite {
     
        private static Scanner clavier = new Scanner(System.in);
     
        public static void main(String[] args) {
     
            int debut;
            do {
                System.out.print("de (>= 1) ? ");
                debut = clavier.nextInt();
            } while (debut < 1);
     
            int fin;
            do {
                System.out.print("a (>= " + debut + ") ? ");
                fin = clavier.nextInt();
            } while (fin < debut);
     
            for (int x = debut; x <= fin; ++x)	{
            int k = 0;
            	do	{
            		if (x % 3 == 0)	{
            			x =+ 4;
            			++k;
            		}
            		if (x % 3 != 0 && x % 4 == 0)	{
            			x = x / 2;
            			++k;
            		}
            		if (x % 3 != 0 && x % 4 != 0)	{
            			x = x - 1;
            			++k;
            		}
            	}	while (x != 0);
     
            	System.out.println(x + " --> " + k);
            }
        }
    }


  2. #2
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    Default Re: help with number game using nested for and doWhile loop

    Modifying the loop control variable inside the loop is a dangerous game and is surely causing the infinite loop. If using the loop control variable is necessary, copy it to another variable each time through the loop before modifying it.

  3. The Following User Says Thank You to GregBrannon For This Useful Post:

    Niu (October 18th, 2013)

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    Default Re: help with number game using nested for and doWhile loop

    Thanks for the insight. I'm a newbie to programming, so am not even sure which one is the "loop control variable." I'm modifying k in order to count how many iterations are necessary to attain zero. I'm modifying x as ordered by the game based on properties of the number. i'm looking into how to copy either of these variables into another variable, but am unsure of how to do so..

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    Default Re: help with number game using nested for and doWhile loop

    I should have specified. The for loop control variable, x, is the one of concern. Since the for loop will continue as long as x <= fin, you've probably done something in the do/while loop that limits x to be less than fin, so the for loop runs forever.

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    Default Re: help with number game using nested for and doWhile loop

    ah yes...especially considering x becomes 0 and fin is greater than 1! thanks again. going to create another variable now...

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