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Thread: doing arithmetic on Integer objects

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    Default doing arithmetic on Integer objects

    Is there a way to do arithmetic on Integer objects? For example, I tried the following without success:

    Integer I = new Integer(1);
    I++;

    I also noticed there is no setValue(int) method in the Integer class, so I can't do this:

    I.setValue(I.intValue() + 1);

    The only way I can think of to change the value of an Integer (or any Number object) through arithmetic is to create a new one based on the value of the old one. So something like this:

    I = new Integer(I.intValue() + 1);

    Is this really the only way to do it?


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    Default Re: doing arithmetic on Integer objects

    Any reason you must rely on an Integer object rather than the primitive? The Integer class is is a wrapper class whose value is final, so to modify it you must create a new Integer object derived from the previous, or use primitives.

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    Default Re: doing arithmetic on Integer objects

    copeg is absolutely correct, but you could also do this:

    Integer i = new Integer(1); //could also be Integer i = 1;
    i = i + 1;

    Google autoboxing.

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    Default Re: doing arithmetic on Integer objects

    Quote Originally Posted by KevinWorkman View Post
    copeg is absolutely correct, but you could also do this:

    Integer i = new Integer(1); //could also be Integer i = 1;
    i = i + 1;

    Google autoboxing.
    Well, the compiler is happy with this.

    I'm using Integers because I'm placing them in a Vector.

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    Default Re: doing arithmetic on Integer objects

    It seems this *can* work (depending on your application), but one should know this operation creates a new Integer object out of the old. So if you had any other references to the old one, they will not point to the new one.

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