In this post, we will understand the difference between HashMap and LinkedHashMap in Java.
HashMap
In this structure, the order of insertion is not preserved.
It uses the HashTable to store maps.
It extends the ‘AbstractMap’.
It implements the ‘Map’ interface.
This was introduced in JDK 2.0.
It has a relatively low overhead.
LinkedHashMap
In this structure, the order of insertion is not preserved.
It uses the HashTable and Linked List to store maps.
It extends the ‘Hashmap’.
It implements the ‘Map’ interface.
This was introduced in JDK 4.0.
It has a relatively higher overhead.
This is because it has to maintain the order of entries in the map structure.