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Singleton Pattern
Last Updated : 26 May, 2026
title: Singleton Design Pattern
Design Patterns40 words4 headingsExamples included
title: Singleton Design Pattern description: Ek hi instance banana - Singleton pattern
Ek class ka sirf ek hi instance banana.
Eager Initialization
java exampleWoHoTech
public class Singleton {
private static final Singleton INSTANCE = new Singleton();
private Singleton() { }
public static Singleton getInstance() { return INSTANCE; }
}Lazy Initialization (Thread-safe)
java exampleWoHoTech
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;
}
}Enum Singleton (Best)
java exampleWoHoTech
public enum Singleton {
INSTANCE;
public void doSomething() { System.out.println("Doing something"); }
}
// Use: Singleton.INSTANCE.doSomething();Use Cases
- Database connection pool
- Logger
- Configuration manager
- Cache manager
Exam Focus
Revise definitions, diagrams, examples, and short-answer points for Singleton Pattern.
Interview Use
Prepare one clear explanation, one practical example, and one common mistake for this Java topic.
Search Terms
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