Gain insights into integrating TypeScript with React to improve productivity. Learn about strongly-typed props, state, and events, and set up projects using Create React App, Webpack, and Babel.

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

# Component without state type specified

We are going to use an exercise in CodeSandbox to work on a `Counter` component. The task will be similar to what we did for the function-based `Counter` component earlier in this course.

Click the link below to open the exercise in CodeSandbox:

[CodeSandbox project](https://codesandbox.io/s/react-ts-class-state-v8oyh?fontsize=14)

We are going to add the current count as a state to the `Counter` component. We'll start by initializing the `count` state:

```
class Counter extends React.Component {
  state = {
    count: 0
  }
  render() {
    return <button>Click to start counter</button>;
  }
}
```

Alternatively, we could initialize the `count` state in a constructor as follows:

```
class Counter extends React.Component {
  constructor(props: {}) {
    super(props);
    this.state = {
      count: 0
    };
  }
  render() {
    return <button>Click to start counter</button>;
  }
}
```

It's up to you which state initialization approach you use - the TypeScript typing works well with both approaches.

Let's also increment the `count` when the button is clicked and output the count in the button:

```
render() {
  return (
    <button onClick={() => this.setState((state) => ({count: state.count + 1}))}>
      {this.state.count ? this.state.count : "Click to start counter"}
    </button>
  );
}
```

The component does function as we want, but we have type errors where the `count` state is referenced:

In this lesson, we are going to learn how to create a strongly-typed state in a class component.

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 strongly-typed class state

Component without state type specified