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

## Understanding a union type

As the name suggests, union types are types that we can combine together to form a new type. A union type is constructed from existing types using the pipe (`|`) character:

```
type A_or_B_or_C = A | B | C;
``` 

Let's go through an example to make this clear. Let's say we have an `age` variable that can be `null` or numeric. How could we create a type for this? Well we can combine the `number` and `null` types in a union type as shown below:

# Understanding a union type

As the name suggests, union types are types that we can combine together to form a new type. A union type is constructed from existing types using the pipe (`|`) character:

```
type A_or_B_or_C = A | B | C;
``` 

Let's go through an example to make this clear. Let's say we have an `age` variable that can be `null` or numeric. How could we create a type for this? Well we can combine the `number` and `null` types in a union type as shown below:

In this lesson, we'll learn what a union type is, how to create one and some cases where they are useful.


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 union types

Understanding a union type #