When to use LinkedList over ArrayList in Java?
When to use LinkedList over ArrayList in Java?
16721-Jul-2023
Updated on 22-Jul-2023
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When to use LinkedList over ArrayList in Java?
Aryan Kumar
22-Jul-2023There are a few reasons why you might want to use a linked list over an array list in Java.
Insertion and deletion are faster in linked lists. When you insert or delete an element from the beginning or end of a linked list, it only requires changing a few pointers. In contrast, when you insert or delete an element from the beginning or end of an array list, it requires moving all of the elements after the insertion or deletion point.
Linked lists are more efficient for iterating over elements in reverse order. To iterate over the elements in a linked list in reverse order, you can simply start at the end of the list and traverse the links backwards. In contrast, to iterate over the elements in an array list in reverse order, you need to reverse the order of the array before iterating over it.
Linked lists are more memory efficient for storing sparse data. A sparse data structure is one where most of the elements are empty. In a linked list, each element only takes up the space required for the element's data and the pointers to the next and previous elements. In contrast, each element in an array list takes up the same amount of space, regardless of whether the element is empty or not.
However, there are also a few reasons why you might want to use an array list over a linked list.
Array lists have random access. You can access any element in an array list by its index. In contrast, you can only access elements in a linked list by traversing the links from the beginning of the list.
Array lists are more efficient for storing dense data. Dense data is data where most of the elements are non-empty. In an array list, each element only takes up the space required for the element's data. In contrast, each element in a linked list takes up the space required for the element's data, the pointers to the next and previous elements, and the space required for the objects that the pointers point to.
Here's a table summarizing the pros and cons of linked lists and array lists:
Ultimately, the best data structure to use depends on your specific needs. If you need to insert or delete elements frequently, or if you need to iterate over the elements in reverse order, then a linked list is a good choice. If you need random access to the elements, or if you need to store dense data, then an array list is a better choice.