How to sort Map values by key in Java?

Let’s say the following is our Map with unsorted keys −

HashMap<String, String>map = new HashMap<String, String>();
map.put("1", "A");
map.put("6", "B");
map.put("3", "C");
map.put("7", "D");
map.put("5", "E");
map.put("2", "F");
map.put("4", "G");
map.put("8", "H");

Now, sort the above Map. The result of tMap below would be a sorted map by key −

Map<String, String>tMap = new TreeMap<String, String>(map);

Example

 Live Demo

import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
public class Demo {
   public static void main(String[] args) {
      HashMap<String, String>map = new HashMap<String, String>();
      map.put("1", "A");
      map.put("6", "B");
      map.put("3", "C");
      map.put("7", "D");
      map.put("5", "E");
      map.put("2", "F");
      map.put("4", "G");
      map.put("8", "H");
      Map<String, String>tMap = new TreeMap<String, String>(map);
      System.out.println("Sorted Map values: "+tMap);
   }
}

Output

{1=A, 2=B, 3=C, 4=D, 5=E, 6=F, 7=G, 8=H}

Karthikeya Boyini

Published on 25-Apr-2019 09:35:54

• Related Questions & Answers
• How can we sort a Map by both key and value using lambda in Java?
• How to sort a dictionary in Python by values?
• Sort Python Dictionaries by Key or Value
• Sort Dictionary key and values List in Python
• How to Sort object of objects by its key value JavaScript
• Java Program to read map by Map.Entry
• Python program to sort tuples in increasing order by any key.
• Java Program to Map String list to lowercase and sort
• Java Program to loop through Map by Map.Entry
• Sort list of dictionaries by values in C#
• Ways to sort list of dictionaries by values in Python
• Sort Tuples in Increasing Order by any key in Python program
• Map values to colors in Matplotlib
• How to use Iterator to loop through the Map key set?
• How to sort a list of dictionaries by values of dictionaries in C#?