If you are a React developer and want to build your React apps faster and more robustly, this course is for you. Learn to integrate TypeScript with React, boost your productivity, and create apps that are easier to maintain.

In this course, you will learn how to utilize TypeScript’s sophisticated type system to make React development faster and your code more readable. You will learn how to create component props, state, and events that are strongly-typed, allowing you to quickly understand what you can pass and helping you avoid mistakes.

Lastly, you will set up React projects with TypeScript. First, you will learn how to do this with the Create React App tool, then how to create a React and TypeScript project with Webpack and Babel.

Using TypeScript with React

## A non-generic function

Below is a function that takes in an array and returns its first element. If the array is empty, `null` is returned.

```
function firstOrNull(array: string[]): string | null {
  return array.length === 0 ? null : array[0];
}
```

This function is strongly-typed, which is excellent; but what if we need to do the same thing for an array of numbers? We can't use the above function because it is restricted for arrays of strings. Wouldn't it be nice if we could pass the array item type into this function? Well, this is what generic functions allow us to.

# A non-generic function

Below is a function that takes in an array and returns its first element. If the array is empty, `null` is returned.

```
function firstOrNull(array: string[]): string | null {
  return array.length === 0 ? null : array[0];
}
```

This function is strongly-typed, which is excellent; but what if we need to do the same thing for an array of numbers? We can't use the above function because it is restricted for arrays of strings. Wouldn't it be nice if we could pass the array item type into this function? Well, this is what generic functions allow us to.

In this lesson, we will learn how to create strongly-typed functions with flexible parameters and return types.

Why TypeScript?

Using basic types

Creating types

Working with generic types

Creating strongly-typed function component props

Creating strongly-typed function component state

Creating strongly-typed class components

Creating strongly-typed component events and event handlers

Creating strongly-typed context

Creating strongly-typed refs

Creating React projects with TypeScript using Create React App

Creating a React and TypeScript project manually

Putting everything together

Creating generic functions

A non-generic function