Gain insights into TypeScript's core concepts, from basics to advanced type checking and iterators. Learn about static typing and JS library support through practical, hands-on experience.

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If you’re looking to move beyond vanilla JavaScript and take your skills to the next level, then you’ve come to the right place. TypeScript is an in-demand language that sits on top of JavaScript. This means you can do everything you can in JavaScript with TypeScript, but also enjoy countless other perks including support for JS libraries, NPM, static typing, and much more.

In this course, you’ll start from the beginning and work your way up to more advanced concepts like type checking, iterators, and manipulating objects and arrays. You'll get a chance to get your hands dirty with plenty of real practice along the way.

For JavaScript developers, TypeScript is a must-know language, not only for today but also for years to come. Don't miss out.

Learn TypeScript: The Complete Course for Beginners

# Nullish coalescing for an object 
**TypeScript 3.7** brought the _nullish coalescing_ operator: `??`. On the left side of the operator is a variable or condition. On the right side is the result **if** the condition is `null` or `undefined`. 

One use case for this operator is to check if a variable is set to define a default value.

The invocation of **line 19** of `myFunction` does not have a second parameter. It causes the code to use the default value on **line 8**.

This lesson explains the new nullish coalescing operator.

Introduction

The Basics of Variables

Comment

Enum

Generic Type

Functions

Mapped Type

Objects

Index Signature

Variables Advanced

Exception

Alias

Type Checking

Iterators

Manipulating Objects and Array

Sharing Code

Conclusion

Nullish Coalescing

Nullish coalescing for an object