Why LinkedList and arraylist extends AbstractList in java?

Question

Why LinkedList and ArrayList extends AbstractList in Java?

Abstract classes are used when we want to specify a common beh

Answer 1

subList(int,int) method is not overriden by both ArrayList and LinkedList, and for this AbstractList provides a common implementation

From Java source

public List subList(int fromIndex, int toIndex) {
        return (this instanceof RandomAccess ?
                new RandomAccessSubList(this, fromIndex, toIndex) :
                new SubList(this, fromIndex, toIndex));
    }

In addition there are other methods which are not overriden like toString() and iterator()