Write functions in TypeScript to declare expected types of function parameters and return values.
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.
### Skills you’ll gain
* Apply type annotations to function parameters.
* Understand how TypeScript determins the return type of a function.
* Explicitly specify return types for functions.
### Notes on prerequisites
We recommend that you complete [Learn TypeScript: Fundamentals](https://www.codecademy.com/learn/learn-typescript-fundamentals) before starting 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.
### Skills you’ll gain
* Apply type annotations to function parameters.
* Understand how TypeScript determins the return type of a function.
* Explicitly specify return types for functions.
### Notes on prerequisites
We recommend that you complete [Learn TypeScript: Fundamentals](https://www.codecademy.com/learn/learn-typescript-fundamentals) before starting this course.
