Java ArrayList and LinkedList differences

ArrayList is the realization of the data structure based on dynamic array, LinkedList data structure based on the linked list.

1. For ArrayList and LinkedList, the overhead of adding an element at the end of the list is fixed. For ArrayList, the main point is to add an entry in the internal array, pointing to the element being added, which may occasionally cause the array to be redistributed, whereas for LinkedList, the overhead is uniform, allocating an internal entry object.

2. Inserting or deleting an element in the middle of a ArrayList means that the remaining elements in the list will be moved, while the overhead of inserting or deleting an element in the middle of the linkedlist is fixed.

3. LinkedList does not support efficient random element access.

4. ArrayList space waste is mainly reflected in the end of the list to reserve a certain amount of space, and the space cost of LinkedList is reflected in its every element needs to consume considerable space

It can be said that using ArrayList provides better performance when the action is to add data after a column of data rather than in front or in the middle, and to randomly access its elements, and when your action is to add or delete data in front or in the middle of a column of data, and to access its elements sequentially, You should use the LinkedList.