Thread: 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)

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
        }
    }
    }
}

"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?

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));
}
 
}

Please read problems with spoonfeeding.

Originally Posted by llowe29

Please read problems with spoonfeeding.

You're funny, or a mess. Not sure which.

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