Java LinkedHashMap class

• A LinkedHashMap contains values based on the key. It implements the Map interface and extends HashMap class.
• It contains only unique elements.
• It may have one null key and multiple null values.
• It is same as HashMap instead maintains insertion order.

Hierarchy of LinkedHashMap class:

Example of LinkedHashMap class:

1.    import java.util.*;  

2.    class TestCollection14{  

3.     public static void main(String args[]){  

4.       

5.      LinkedHashMap<Integer,String> hm=new LinkedHashMap<Integer,String>();  

6.      

7.      hm.put(100,"Amit");  

8.      hm.put(101,"Vijay");  

9.      hm.put(102,"Rahul");  

10.   

11. for(Map.Entry m:hm.entrySet()){  

12.    System.out.println(m.getKey()+" "+m.getValue());  

13.   }  

14.  }  }

Output:100 Amit

       101 Vijay

       103 Rahul