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Thread: Instance Variables and local variables difference

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    Default Instance Variables and local variables difference

    I have a question about instance variables and local variables...

    When you have an instance variable defined outside of every method but inside a class (say variable named "X"), and you create a local variable the same name ("X") within a certain method, will the instance variable get changed? There are two examples below.

    private int X;
     
    private void test(int y)
    {
         int X;
     
         X = y;
    }

    Will the variable X will be changed within the method, but will that change the instance variable X?

    private int X
     
    private void test(int X)
    {
         X = X + 1;
    }

    How about the example above? Does the local variable take precedence over the global variable in those cases?


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    Default Re: Instance Variables and local variables difference

    You have written the code. Why don't you compile and run it to see what happens?
    Improving the world one idiot at a time!

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    Default Re: Instance Variables and local variables difference

    See: Java Gotchas: Instance Variables Hiding | JAVA Developer's Journal.

    For more information, do a search on Java variable hiding.

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    Default Re: Instance Variables and local variables difference

    The second code snippet won't compile .

    Now, to refer the outer variable, you might use this.X. That should do the work, otherwise it's refered only locally.

    application context
    Last edited by daniel.j2ee; December 13th, 2011 at 03:57 PM.

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