The ultimate guide to coding interviews: Learn and practice JavaScript design patterns tested by FAANG engineers. Get interview-ready in just a few hours with battle-tested solutions.

If you're an experienced developer, chances are your interviewer won't ask you about language syntax. Instead, they'll focus on things that test your understanding of software architecture, and how capable you are at finding optimized solutions to given problems. 

That’s where a strong understanding of design patterns comes in handy. It's often useful to be able to draw on established patterns instead of reinventing the wheel.

In this course, you will learn how to effectively deploy design patterns to answer interview questions. The course is divided into four sections: Creational Patterns, Structural Patterns, Behavioral Patterns, and Architectural Patterns. Each section has its own set of design patterns which you’ll learn to use through various challenges. 

Every challenge contains a detailed solution explanation. By the end of this course (and with some practice), you will be able to confidently use design patterns to tackle advanced coding interview questions in JavaScript.

JavaScript Design Patterns for Coding Interviews

## What is the singleton pattern?

The **singleton pattern** is a type of creational pattern that restricts the instantiation of a class to a **single** object. This allows the class to create an instance of the class the first time it is instantiated. However, on the next try, the existing instance of the class is returned. *No new instance is created*.  


# What is the singleton pattern?

The **singleton pattern** is a type of creational pattern that restricts the instantiation of a class to a **single** object. This allows the class to create an instance of the class the first time it is instantiated. However, on the next try, the existing instance of the class is returned. *No new instance is created*.  


In this lesson, you will learn about the singleton pattern in detail with the help of a coding example.

Before We Begin

Introduction To Design Patterns

Creational Patterns

Structural Patterns

Behavioral Patterns

Architectural Patterns

Conclusion

Singleton Pattern

What is the singleton pattern?