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 visitor pattern?

The visitor pattern allows the definition of new operations to the collection of objects without changing the structure of the objects themselves. This allows us to separate the class from the logic it implements. 

The extra operations can be encapsulated in a **visitor** object. The objects can have a **visit** method that accepts the **visitor** object. The **visitor** can then make the required changes and perform the operations on the object that received it. This allows the developers to make future extensions, extend the libraries/frameworks, etc.

# What is the visitor pattern?

The visitor pattern allows the definition of new operations to the collection of objects without changing the structure of the objects themselves. This allows us to separate the class from the logic it implements. 

The extra operations can be encapsulated in a **visitor** object. The objects can have a **visit** method that accepts the **visitor** object. The **visitor** can then make the required changes and perform the operations on the object that received it. This allows the developers to make future extensions, extend the libraries/frameworks, etc.

You will go over the visitor pattern in detail with the help of a coding example in this lesson.


Before We Begin

Introduction To Design Patterns

Creational Patterns

Structural Patterns

Behavioral Patterns

Architectural Patterns

Conclusion

Visitor Pattern

What is the visitor pattern?