TypeScript is a programming language built on top of JavaScript, that allows developers to specify types for data being referenced or passed around in the script. This precision around data types enables developers to write cleaner, more intentional code and helps developers more easily catch errors and debug their programs.

What does TypeScript do?

TypeScript allows developers to specify the type of data being referenced in their code. It can throw errors when the expected type doesn’t match the output. For example, with TypeScript, developers can specify that a given function should return a number. If a call tot he function returns a string instead, TypeScript will throw an error that will help the developer more easily identify the issue in their code.

What kind of jobs use TypeScript?

Because TypeScript is a superset of JavaScript, that is, it adds additional features to the JavaScript language, it can be used anywhere the JavaScript is used. It is commonly used by web developers on both the front and back end of the stack.

What else should I study if I am learning TypeScript?

It can be helpful to have a foundation of JavaScript before learning TypeScript as this will make the learning curve of specifying types a bit more intuitive. TypeScript is commonly used in across the full stack of web development so knowing which side of the stack you want to specialize in will be helpful in guiding next steps for learning. Folks who want to lean towards the front-end will want to learn HTML, CSS, and other relevant front-end frameworks like React and Redux. Those wanting to dive deeper into the back end will want to learn a database management system and relevant back-end frameworks like Express. Of course, you can be a full-stack developer and do it all!

Course

Learn Intermediate TypeScript

Dive into intermediate TypeScript concepts including class types, type narrowing, and generics.

This course includes

Skill level
Intermediate
Time to complete
Average based on combined completion rates — individual pacing in lessons, projects, and quizzes may vary

3 hours
Projects
3
Prerequisites
1 course

We suggest you complete the following courses before you get started with Learn Intermediate TypeScript:
Learn TypeScript

About this course

This comprehensive course on TypeScript takes you from setting up TypeScript in VSCode to mastering its intermediate concepts and features. You’ll learn how to install TypeScript globally and for specific projects in VSCode on your local computer, apply TypeScript types to classes to control how class properties and methods are used. You’ll also learn how TypeScript does type narrowing, use type guards, and apply generics with classes, type parameter defaults and constraints.Through practical examples password generator and currency converter apps, you’ll gain hands-on experience in using these concepts.

Skills you'll gain

Set up TypeScript in VSCode on your local computer
Apply types to object-oriented programming patterns
Utilize TypeScript’s power of inference through type narrowing and type guards
Create reusable code with TypeScript generics

Syllabus

3 lessons • 3 projects • 4 quizzes

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Meet the full team

Kenny Lin

Web Development Domain Manager at Codecademy

Kenny is the Domain Manager for the Web Development Domain at Codecademy. He contributed to a wide range of courses and paths at Codecademy, including JavaScript, Bootstrap, Handlebars, Phaser.js, Go, Swift, TypeScript, and Lua.

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Frequently asked questions about Intermediate TypeScript

TypeScript is a programming language built on top of JavaScript, that allows developers to specify types for data being referenced or passed around in the script. This precision around data types enables developers to write cleaner, more intentional code and helps developers more easily catch errors and debug their programs.

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Learn Intermediate TypeScript

About this course

Skills you'll gain

Syllabus

TypeScript Configuration

TypeScript Class Types

Intermediate Type Narrowing

TypeScript Generics