The ArrayList index starts at 0 just like arrays, but instead of using the square brackets [] to access elements, you use the get(index) to get the value at the index and set(index,value) to set the element at an index to a new value.

Can an ArrayList be size 0?

Another way to check if arraylist contains any element or not, we can check the size of arraylist. If the list size is greater than zero, then list is not empty. If list size is 0, list is empty. If we look inside the isEmpty() method, it also check the size of arraylist to determine if the list is empty or not.

Does an ArrayList start at 0 or 1?

Arrays index starts from zero in java.