In Java, the LinkedList and ArrayList classes are both used to store and manage a collection of objects. However, there are some differences between the two classes that you should be aware of when choosing which one to use in your code.
Here are some situations where you should use a LinkedList over an ArrayList in Java:
If you need to frequently add and remove elements from the middle of the list. LinkedList is implemented as a doubly-linked list, which allows for efficient insertion and removal of elements at arbitrary positions in the list. In contrast, ArrayList is implemented as an array, so inserting or removing an element in the middle of the list requires shifting all of the subsequent elements to make room, which can be slow.
If you need to iterate over the elements of the list in both forward and backward directions. Because LinkedList is a doubly-linked list, you can easily move backwards and forwards through the list, which is not possible with an ArrayList, which is a linear structure.
If you have a large number of elements and you need to minimize memory usage. LinkedList uses less memory than ArrayList because it only stores the elements and references to the next and previous elements in the list, while ArrayList stores the elements and an array to hold the elements, which requires more memory.
In general, LinkedList is a good choice when you need a more flexible and efficient list data structure, while ArrayList is a better choice when you need a simple and efficient way to store
Top comments (1)
LinkedLists don't use less memory than an ArrayList. In fact, most of the time they use more.
LinkedList with n elements:
ArrayList with n elements added one at a time:
ArrayList with n elements specifying internal array size at time of construction or using
trimToSize()method that decreases length to current size:
Also traversing an ArrayList backwards is not a problem. Easily done in either direction. Just decrement indexes instead if incrementing.
The only real advantage to LinkedList over ArrayList is inserting or removing from interior of LinkedList.