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Thread: convert double to int in ArryList

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    Default convert double to int in ArryList

    Hello,

    assume that i have the flowing arrayList:

    ArrayList arr = new arrayList();
    arr.add("hi");
    arr.add(2.5);
    arr.add("x");
    arr.add(2.9);
    arr.add(1.0);

    now i want to convert every double value in arr to integer, how to do that (just the double and ignore another types)


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    Default Re: convert double to int in ArryList

    This thread has been cross posted here:

    http://www.java-forums.org/new-java/80627-convert-double-int-arrylist.html

    Although cross posting is allowed, for everyone's benefit, please read:

    Java Programming Forums Cross Posting Rules

    The Problems With Cross Posting

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    Default Re: convert double to int in ArryList

    public static void main(String[] args) {
            ArrayList arr = new ArrayList();
            arr.add("hi");
            arr.add(2.5);
            arr.add("x");
            arr.add(2.9);
            arr.add(1.0);
     
            for(int i = 0; i < arr.size(); i++){
            if (arr.get(i) instanceof Double ){
                (int)arr.get(i); //false, but how to do it correctly
            }
        }
        }
    }

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    Default Re: convert double to int in ArryList

    "how to do it correctly" does not explain very much about the problem you face.
    Is there an error?
    Is the array just left unchanged, where you expected to see a change?

    The line of code (int)arr.get(i); has no side effect, did you expect this to modify a value in the array?

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    Default Re: convert double to int in ArryList

    Simple answer is DO NOT insert different types into the same List.
    Improving the world one idiot at a time!

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    Default Re: convert double to int in ArryList

    Simple answer is DO NOT insert different types into the same List
    Some times you don't have any another choice, any way the solution to do it

    public static void main(String[] args) {
        ArrayList arr = new ArrayList();
        arr.add("hi");
        arr.add(2.5);
        arr.add("x");
        arr.add(2.9);
        arr.add(1.0);
     
        for(int i = 0; i < arr.size(); i++){
        if (arr.get(i) instanceof Double ){
             int n = ((Double) arr.get(i)).intValue(); 
             arr.set(i, n);
        }
        System.out.println(arr.get(i));
    }
     
    }

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    Member llowe29's Avatar
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    Default Re: convert double to int in ArryList

    Please read problems with spoonfeeding.

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    Default Re: convert double to int in ArryList

    Quote Originally Posted by llowe29 View Post
    Please read problems with spoonfeeding.
    He was posting the solution to his own problem. The user who posted the solution *is* the OP. This is actually pretty okay.
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    Default Re: convert double to int in ArryList

    Quote Originally Posted by llowe29 View Post
    Please read problems with spoonfeeding.
    You're funny, or a mess. Not sure which.

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    Member llowe29's Avatar
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    Default Re: convert double to int in ArryList

    I didn't realize it was his own thread sorry lol.

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