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Thread: Is it possible to add only String and Integer to ArrayList(Must be generic) by using JAVA GENERICS

  1. #1
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    Default Is it possible to add only String and Integer to ArrayList(Must be generic) by using JAVA GENERICS

    Hi

    any one please help to solve title problem....

    Problem like:

    i am interested to add integer objects and String objects into any collection object ..... if it is possible please provide source code..

    while iterating the collection object i am not interested to do any type cast in java


    Thanks in advance...


  2. #2
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    Default Re: Is it possible to add only String and Integer to ArrayList(Must be generic) by using JAVA GENERICS

    Not directly. But you can implement a new class (or interface) that can wrap-up either a String or an Integer and then store this class in your collection.

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    Default Re: Is it possible to add only String and Integer to ArrayList(Must be generic) by using JAVA GENERICS

    If two different types are in the arraylist, how will the code know which type is returned by the get() method?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Is it possible to add only String and Integer to ArrayList(Must be generic) by using JAVA GENERICS

    List<Object> list = new ArrayList<Object>();
    	list.add(new Integer(1));
    	list.add(new String("Tom"));
    	System.out.println(list);

    I really dont know why I'm writing this..kind of defeats the whole purpose of using generics in Java, which happens to be a compile time check to help the developer write a better code(which is, not to put an Integer in a list of String)..Probably you can tell us about what is the problem statement that you are trying to solve rather than trying to come up with a solution on your own and then asking for that solution ?
    Last edited by dextr; August 29th, 2014 at 11:29 AM.

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