What is the Singleton pattern and how do you implement it thread-safely? | Interview Question | TechyTalkWithDev

What is the Singleton pattern and how do you implement it thread-safely? | Interview Question | TechyTalkWithDev

Thread-Safe Singleton (Double-Checked Locking)

java

public class Singleton {
    private static volatile Singleton instance;

    private Singleton() {}

    public static Singleton getInstance() {
        if (instance == null) {
            synchronized (Singleton.class) {
                if (instance == null) {
                    instance = new Singleton();
                }
            }
        }
        return instance;
    }
}