Java Collection, TreeMap Exercises: Remove and get a key-value mapping associated with the least key in a map

Java Collection, TreeMap Exercises: Exercise-19 with Solution

Write a Java program to remove and get a key-value mapping associated with the least key in a map.

Sample Solution:-

Java Code:

import java.util.*;
import java.util.Map.Entry;  
public class Example19 {  
         public static void main(String args[]) {

  // Create a tree map
  TreeMap < Integer, String > tree_map = new TreeMap < Integer, String > ();

  // Put elements to the map 
  tree_map.put(10, "Red");
  tree_map.put(20, "Green");
  tree_map.put(40, "Black");
  tree_map.put(50, "White");
  tree_map.put(60, "Pink");

  // polling first entry
  System.out.println("Value before poll: " + tree_map);
  System.out.println("Value returned: " + tree_map.pollFirstEntry());
  System.out.println("Value after poll: " + tree_map);

Sample Output:

Value before poll: {10=Red, 20=Green, 40=Black, 50=White, 60=Pink}     
Value returned: 10=Red                                                 
Value after poll: {20=Green, 40=Black, 50=White, 60=Pink}

Java Code Editor:

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Java: Tips of the Day

Choice between Float and Double:

Data type Bytes used Significant figures (decimal)
Float 4 7
Double 8 15

Double is often preferred over float in software where precision is important because of the following reasons:
Most processors take nearly the same amount of processing time to perform operations on Float and Double. Double offers far more precision in the same amount of computation time.

Ref: https://bit.ly/3oj7K2K