Let's talk about Java Array List and Linked List here.
Array List:
Features-- ArrayList class implements List interface (and a couple more) and extends AbstractList class.
- ArrayList is a re-sizable array implementation which means it can automatically grow its size if required.
- ArrayList is internally backed by an Array.
- Duplicates are allowed.
- Not thread safe.
How it works:
- When we instantiate an ArrayList, it actually creates an Array of default capacity of 10 using no argument constructor.
- When we add elements to the list, it stores the elements inside that array. Once this array gets full, it automatically creates a new array of larger capacity than the previous array (typically 1.5 time larger) and copies all the elements from old array to the new larger array.
- However it does not shrink its size if we keep deleting the elements from it.
Linked List:
Features-
- Doubly Linked List implementation of Linked List (Abstract Data Type) provided by Java.
- LinkedList class implements following interface:
- List
- Deque
- Clonable
- Serializable
- Iterable
- Collection
- Queue
- It extends AbstractSequentialList class.
- Duplicates are allowed.
- Uses Nodes to store elements.
- Dynamic memory allocation i.e. nodes will be created when required.
- Not thread safe.
