IndexOutOfBoundsException when adding to ArrayList at index

Question

I get exception Exception in thread \"main\" java.lang.IndexOutOfBoundsException: Index: 1, Size: 0 for the below code. But couldn\'t understand why.

Answer 1

You can initialize the size (not the capacity) of an ArrayList in this way:

ArrayList list = new ArrayList(Arrays.asList(new T[size]));

in your case:

ArrayList s = new ArrayList(Arrays.asList(new String[10]));

this creates an ArrayList with 10 null elements, so you can add elements in random order within the size (index 0-9).