Java Singleton Pattern HackerRank Solution

Hello Programmers, In this post, you will know how to solve the Java Singleton Pattern HackerRank Solution. This problem is a part of the HackerRank Java Programming Series.

Java Singleton Pattern HackerRank Solution
Java Singleton Pattern HackerRank Solutions

One more thing to add, don’t directly look for the solutions, first try to solve the problems of Hackerrank by yourself. If you find any difficulty after trying several times, then you can look for solutions.

Java Singleton Pattern HackerRank Solutions


“The singleton pattern is a design pattern that restricts the instantiation of a class to one object. This is useful when exactly one object is needed to coordinate actions across the system.”
– Wikipedia: Singleton Pattern

Complete the Singleton class in your editor which contains the following components:

  1. private Singleton non parameterized constructor.
  2. public String instance variable named .
  3. Write a static method named getSingleInstance that returns the single instance of the Singleton class.

Once submitted, our hidden Solution class will check your code by taking a String as input and then using your Singleton class to print a line.

Input Format

You will not be handling any input in this challenge.

Output Format

You will not be producing any output in this challenge.

Sample Input

hello world

Sample Output

Hello I am a singleton! Let me say hello world to you

Java Singleton Pattern HackerRank Solutions

import java.util.Scanner;
import java.lang.reflect.Constructor;
class Singleton {
    private Singleton() {}
    public String str;
    private static Singleton instance = null;
    public static Singleton getSingleInstance() {
        if (instance == null) {
            instance = new Singleton();
        return instance;

Disclaimer: The above Problem (Java Singleton Pattern) is generated by Hackerrank but the Solution is Provided by BrokenProgrammers. This tutorial is only for Educational and Learning purposes.

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