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Thread: Type magic

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    Default Type magic

    I used a DefaultListModel to populate a JList.

    Example: dlm.addElement(s); where s=String

    When I retrieve a value from the JList using the index of dlm, it works great
    When I output text -- "JList points to : " + lm.elementAt(idx) -- this also works great

    When I attempt -- s = lm.elementAt(idx); javac flags me with:

    incompatible types
    found : java.lang.Object
    required: java.lang.String

    is there a handy method for getting my String back? A few times in the past I have gotten into similar type issues where I pick up some output and go to its type, at which class there is a method that sounds like it may get closer, but it only outputs to class x ... and so on, and never do get what I needed in the first place. Hoping I missed something simple.



    TIA


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    Default Re: Type magic

    I'm not really sure what you're talking about- could you provide an SSCCE that demonstrates what you mean?
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    Default Re: Type magic

    Is SSCCE same as Java source in whole program form?

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    Default Re: Type magic

    Quote Originally Posted by meathead View Post
    Is SSCCE same as Java source in whole program form?
    No. Did you click the link I gave you? It's a very simplified program, only a few lines long, that very specifically demonstrates what you're talking about.
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    Default Re: Type magic

    Oops!


    Object o = lm.elementAt(idx);
    sGet = o.toString();
    jlabChoose.setText("JList points to : " + sGet);


    thanks for the offer, sorry for the bother. I can't believe this has been holding me up. Seems like a klug way to go about things, but I don't mean to sound ungrateful to Gosling & the crew.

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    Default Re: Type magic

    The elementAt() method returns an Object- that just means you can put any Object into it. String is an Object. But you could also put other stuff into it (Integers, other Objects), which is why the class can't guarantee you're getting a String.

    I believe that what you're looking for is a simple cast, which tells Java what kind of Object an instance is:

    String sGet = (String) lm.elementAt(idx);
    Last edited by KevinWorkman; October 19th, 2011 at 12:17 PM.
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