LinkedHashMap in java with example

LinkedHashMap is same as HashMap except that it maintains insertion order.

Some points about LinkedHashMap

1. LinkedHashMap implements Map interface and extends HashMap class.
2. LinkedHashMap maintains insertion order, so when you will be able to access elements in the order they were inserted like ArrayList.
3. LinkedHashMap maintains doubly Linked list to maintain insertion order.

Example:

LinkedHashMapMain.java

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package org.arpit.java2blog;   import java.util.LinkedHashMap;   public class LinkedHashMapMain {   public static void main(String args[]) { // LinkedHashMap with Country as key and capital as value // LinkedHashMap maintains insertion order   LinkedHashMap<String,String> countryCapitalMap=new LinkedHashMap<String,String>(); countryCapitalMap.put("India","Delhi"); countryCapitalMap.put("Japan","Tokyo"); countryCapitalMap.put("France","Paris"); countryCapitalMap.put("Russia","Moscow");   System.out.println("-----------------------------"); // Iterating Using keySet() and for each loop System.out.println("Iterating Using keySet() and for each loop"); for (String countryKey:countryCapitalMap.keySet()) { System.out.println("Country:"+ countryKey +" and  Capital:"+countryCapitalMap.get(countryKey));   } System.out.println("-----------------------------"); }   }

If you may iterate LinkedHashMap in multiple ways.
When you run above program, you will get below output:

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----------------------------- Iterating Using keySet() and for each loop Country:India and  Capital:Delhi Country:Japan and  Capital:Tokyo Country:France and  Capital:Paris Country:Russia and  Capital:Moscow -----------------------------