Free
Course

Learn TypeScript: Functions

Write functions in TypeScript to declare expected types of function parameters and return values.

4.63 out of 5 stars
2,847 learners enrolled
  • Skill level

    Beginner
  • Time to complete

    Average based on combined completion rates — individual pacing in lessons, projects, and quizzes may vary
    1 hour
  • Certificate of completion

    Included with paid plans
  • Prerequisites

    None

About this course

Continue your TypeScript learning journey with Learn TypeScript: Functions. In addition to variable types, TypeScript allows you to declare the expected types of your function parameters and infer the types returned by those functions.

Syllabus

The platform

Hands-on learning

Animated GIF of an AI provided error explanation within Codecademy's learning environment
An AI-generated hint within the instructions of a Codecademy project
Animated GIF of Codecademy's Job Readiness Checker tool generating a compatibility report for a senior software engineer role
Animated GIF of building a phone screen interview using Codecademy's Interview Simulator
A fill-in-the-blank JavaScript question in a Codecademy assessment
Meet the creator of the course
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.

Earn a certificate of completion

Show your network you've done the work by earning a certificate of completion for each course or path you finish.
  • Show proofReceive a certificate that demonstrates you've completed a course or path.
  • Build a collectionThe more courses and paths you complete, the more certificates you collect.
  • Share with your networkEasily add certificates of completion to your LinkedIn profile to share your accomplishments.

Learn TypeScript: Functions course ratings and reviews

4.63 out of 5 stars
97 ratings
  1. 5 stars
  2. 4 stars
  3. 3 stars
  4. 2 stars
  5. 1 star
  • The progress I have made since starting to use codecademy is immense! I can study for short periods or long periods at my own convenience - mostly late in the evenings.
    Chris
    Codecademy Learner @ USA
  • I felt like I learned months in a week. I love how Codecademy uses learning by practice and gives great challenges to help the learner to understand a new concept and subject.
    Rodrigo
    Codecademy Learner @ UK
  • Brilliant learning experience. Very interactive. Literally a game changer if you're learning on your own.
    John-Andrew
    Codecademy Learner @ USA

Our learners work at

  • Google Logo
  • Meta Logo
  • Apple Logo
  • EA Logo
  • Amazon Logo
  • IBM Logo
  • Microsoft Logo
  • Reddit Logo
  • Spotify Logo
  • Uber Logo
  • YouTube Logo
  • Instagram Logo

Join over 50 million learners and start Learn TypeScript: Functions today!

Unlock additional features with a paid plan

  • Practice Projects

    Guided projects that help you solidify the skills and concepts you're learning.
  • Assessments

    Auto-graded quizzes and immediate feedback help you reinforce your skills as you learn.
  • Certificate of Completion

    Earn a document to prove you've completed a course or path that you can share with your network.