LinkedHashMap: Introduction

A HashMap does not maintain insertion order and TreeMap stores the elements in sorted order. Now, if we want to store the elements in a Map in insertion order, then a LinkedHashMap can be used. LinkedHashMap is a class in the java.utils package that implements the Map interface and extends the HashMap class. It is similar to HashMap with the additional feature of maintaining the order of elements inserted into it.

Some of the important features of a LinkedHashMap are:

1. It does not allow duplicate keys.
2. It may have one null key and multiple null values.
3. It is non-synchronized.