What are Java List types? What are their methods and what are their properties?

Here are java.util.List implementations and their properties:

1. ArrayList: fast iteration, random access
2. LinkedList: insertion order, fast insertion/deletion
3. Vector: fast iteration, random access, synchronized

Methods common for List implementations:

• boolean add(E): adds element to the list
• boolean add(int index, E): insert element E to the specified position
• boolean contains(Object): checks whether the list contains specified element
• E get(int index): returns an element from the specified position on list
• int indexOf(Object): returns index of first occurrence of given element or -1 if not found
• Iterator<E> iterator(): returns list iterator in correct order
• E remove(int index): removes element from specified position on list and returns it
• boolean remove(Object): removes the first occurrence of given object
• int size(): returns a number of elements in the list
• Object[] toArray(): returns an array containing all list’s elements in proper order (from the first to the last)
• <T> T[] toArray(T[]): returns an array containing all list’s elements in proper order, with type T equal the formal type parameter.

It’s important to know the implementations and these methods if you want to take Oracle Certified Programmer exam.