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Thread: Help Passing Variables

  1. #1
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    Default Help Passing Variables

    I am running this code below:
    	public static void Check(int masterNumber)
    	{
    	int reverseIt = 0;
     
    		for (int i=0; i<=masterNumber; i++)
    		{
    			int r = masterNumber%10;
    			masterNumber = masterNumber/10;
    			reverseIt = reverseIt * 10 + r;
    			i=0;
    		}
     
    	Finalize(masterNumber, reverseIt);
    	}

    masterNumber is being passed in from a module above, and of course reverse it is being declared here in this module. At the end Finalize is being called and both variables are being passed into this method. The problem I am having is masterNumber is being overwritten in this module, so when it get's passed it is showing a null value. What do I need to change in order that masterNumber keeps it's original value declared in it's module?


  2. #2
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    Default Re: Help Passing Variables

    Well, first off, I'm not sure why masterNumber would be null. I don't think ints can even be null...

    Second, masterNumber is being changed in your for statement, by the line:
    masterNumber = masterNumber/10;
    The only way to keep the value that was sent to the method is by declaring another local variable, setting its value to masterNumber, and then performing your operations on the new local variable. Since int is just a primitive, saying:
    int var = masterNumber;
    will set var to the current value of masterNumber, opposed to its location in memory, meaning you can make changes to var or masterNumber without effecting the other variable.
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  3. #3
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    Default Re: Help Passing Variables

    Quote Originally Posted by aussiemcgr View Post
    int var = masterNumber;
    .
    Such a simple solution! I don't know why I didn't think of that! One more question...I think I have my if...else statement set up improperly. What it is supposed to do is if masterNumber equals reverseIt then display they match. If masterNumber does not equal reverseIt display No Match. But it is displaing they match regardless of the case.

    		if(masterNumber != reverseIt)
     
    			JOptionPane.showMessageDialog(null, "They match");
     
    			else
     
    				JOptionPane.showMessageDialog(null, "No match");

    Does that look set up properly to you?

  4. #4
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    Default Re: Help Passing Variables

    print out the values of both variables before the if test so you can see their values and know why the if statement is doing what it is doing.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Help Passing Variables

    When I print the value of the variables, they display properly (as they should). That's why I was curious if I wrote my If statement wrong.

  6. #6
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    Default Re: Help Passing Variables

    If you print the values of the variables, then you should not be surprised by what the if statement does.
    Can you explain? Post the values that are printed and what message was displayed.
    If you don't understand my answer, don't ignore it, ask a question.

  7. The Following User Says Thank You to Norm For This Useful Post:

    jo15765 (May 7th, 2012)

  8. #7
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    Default Re: Help Passing Variables

    I was comparing the wrong 2 variables. Beginner's error. Thank you for the help! (As well as the future tip of printing the variables when results are not looking like I think they should)

  9. #8
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    Default Re: Help Passing Variables

    I use printlns a lot when I'm wondering what the computer is seeing.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Help Passing Variables

    How would I use that?

  11. #10
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    Default Re: Help Passing Variables

    A sample:
       System.out.println("M @ " + getPos(Mouse) + " cheese @ " + getPos(Cheese));
     
         System.out.println("  after set row=" + oldRow + ", col=" + oldCol + " sqr=" + maze[oldRow][oldCol]);
    Last edited by Norm; May 7th, 2012 at 09:19 PM.
    If you don't understand my answer, don't ignore it, ask a question.

  12. #11
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    Default Re: Help Passing Variables

    Cool I'll make a note of this, and use it in future coding projects!

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    Default Re: Help Passing Variables

    Quote Originally Posted by jo15765 View Post
    if(masterNumber != reverseIt) JOptionPane.showMessageDialog(null, "They match");
    else JOptionPane.showMessageDialog(null, "No match");
    you wrote:

    if masterNumber is not equal to reverseIt then display "They Match"
    else (if masterNumber is equal to reverseIt) display "No Match"

    try:
    if(masterNubmer.equals(reverseIt) JOptionPane.showMessageDialog(null, "They Match!");
    else JOptionPane.showMessageDialog(null, "No Match.");
    Last edited by TheNextBillGates; May 7th, 2012 at 09:19 PM. Reason: fix tags

  14. #13
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    Default Re: Help Passing Variables

    if(masterNubmer.equals(reverseIt)
    @TheNextBillGates
    Do you know if the variables are object references or primitives?
    If you don't understand my answer, don't ignore it, ask a question.

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