NavigableMap pollFirstEntry() method in Java

Java 8Object Oriented ProgrammingProgramming

The pollFirstEntry() method in NavigableMap remove and return a key-value mapping associated with the least key in this map

The following is an example to implement pollFirstEntry() method


 Live Demo

import java.util.*;
public class Demo {
   public static void main(String[] args) {
      NavigableMap<Integer, String> n = new TreeMap<Integer, String>();
      n.put(5, "Tom");
      n.put(9, "John");
      n.put(14, "Jamie");
      n.put(1, "Tim");
      n.put(4, "Jackie");
      n.put(15, "Kurt");
      n.put(19, "Tiger");
      n.put(24, "Jacob");
      System.out.println("NavigableMap elements...
"+n); System.out.println("
Removed (first) key-value is "+n.pollFirstEntry()); System.out.println("
Updated NavigableMap elements...
"+n); } }


NavigableMap elements...
{1=Tim, 4=Jackie, 5=Tom, 9=John, 14=Jamie, 15=Kurt, 19=Tiger, 24=Jacob}
Removed (first) key-value is 1=Tim
Updated NavigableMap elements...
{4=Jackie, 5=Tom, 9=John, 14=Jamie, 15=Kurt, 19=Tiger, 24=Jacob}
Updated on 30-Jul-2019 22:30:24