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Java Arraylist remove multiple element by index

Here is my code:

for (int i = 0; i < myarraylist.size(); i++) {
        for (int j = 0; j < stopwords.size(); j++) {
            if (stopwords.get(j).equals(myarraylist.get(i))) {
                myarraylist.remove(i);
                id.remove(i);
                i--; // to look at the same index again!
            }
        }
    }

I have problem.. after element removed, all index always changed, the loop above so messy.

To illustrate: I have 54 data, but loop above become messy after element removed.. so only 50 data that checked.

Is there another way or fix my code to remove multiple element by index?? element index is so important to me, to remove another arraylist that have the same index.

like image 886
Lita Avatar asked Apr 15 '15 16:04

Lita


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1 Answers

One thing you need to keep in mind is that when you use ArrayLists that they are meant to be versatile, moreso than Arrays. You can shorten an array by removing an entire index, add an index to it, and do wonderfulness with ArrayLists.

This is a common problem with people who do not realize, or remember, that when you remove a value, the ArrayList indexes (or whatever the correct plural is) readjust and the ArrayList shortens.

When attempting to remove elements from an ArrayList, you should always start at the end of the ArrayList.

for(int x = arrayList.size() - 1; x > 0; x--)
{
    arrayList.remove(x);
}

This should provide you with the function that you are looking for. Take a look at the ArrayList API for other methods that may help you.

like image 199
Ungeheuer Avatar answered Sep 28 '22 20:09

Ungeheuer