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

```
<input type="text" onKeyDown={e=>console.log(e.key)} />
```

```
<input type="text" onKeyDown={e:React.KeyboardEvent<HTMLInputElement> => console.log(e.key)} />
```

```
<input type="text" onKeyDown={(e: React.KeyboardEvent) => console.log(e.key)} />
```

We have an `input` HTML element in a components JSX: 

```
<input type="text" />
```

How can we add a strongly-typed event handler to the `input` for the `keydown` event, to output the keys pressed to the console.

<p>We have an <code>input</code> HTML element in a components JSX:</p>
<pre><code>&lt;input type=&quot;text&quot; /&gt;
</code></pre>
<p>How can we add a strongly-typed event handler to the <code>input</code> for the <code>keydown</code> event, to output the keys pressed to the console.</p>


```
const handleSubmit = (e: React.FormEvent) => {
  e.preventDefault();
  ...
};
```

```
const handleSubmit = (e: React.FormEvent<HTMLFormElement>) => {
  e.preventDefault();
  ...
};
```

We have a `Search` React component below: 

```
function Search() {
  const handleSubmit = e => {
    e.preventDefault();
    ...
  };
  return (
    <form onSubmit={handleSubmit} >
      <input
        name="search"
        type="text"
      />
    </form>
  );
}
```

How can we make the `handleSubmit` event handler, strongly-typed?

<p>We have a <code>Search</code> React component below:</p>
<pre><code>function Search() {
  const handleSubmit = e =&gt; {
    e.preventDefault();
    ...
  };
  return (
    &lt;form onSubmit={handleSubmit} &gt;
      &lt;input
        name=&quot;search&quot;
        type=&quot;text&quot;
      /&gt;
    &lt;/form&gt;
  );
}
</code></pre>
<p>How can we make the <code>handleSubmit</code> event handler, strongly-typed?</p>


```
type Props = {
  checked: boolean;
};
const Tickbox: React.FC<Props> = ({ children, checked }) => (
  <label>
    {children}
    <input type="checkbox" checked={checked} />
  </label>
);
```

```
type Props = {
  checked: boolean;
  onChecked: (checked: boolean) => void;
};
const Tickbox: React.FC<Props> = ({ children, checked, onChecked }) => (
  <label>
    {children}
    <input
      type="checkbox"
      checked={checked}
      onChange={e => onChecked(e.currentTarget.checked)}
    />
  </label>
);
```

```
type Props = {
  checked: boolean;
  onChecked: () => void;
};
const Tickbox: React.FC<Props> = ({ children, checked, onChecked }) => (
  <label>
    {children}
    <input type="checkbox" checked={checked} onChange={onChecked} />
  </label>
);
```

We have a tickbox component below:

```
const Tickbox: React.FC = ({ children }) => (
  <label>
    {children}
    <input type="checkbox" />
  </label>
);
```

How can we add props so that the checked state of the tickbox can be controlled by the consumer of the component?

<p>We have a tickbox component below:</p>
<pre><code>const Tickbox: React.FC = ({ children }) =&gt; (
  &lt;label&gt;
    {children}
    &lt;input type=&quot;checkbox&quot; /&gt;
  &lt;/label&gt;
);
</code></pre>
<p>How can we add props so that the checked state of the tickbox can be controlled by the consumer of the component?</p>


Creating strongly-typed events and event handlers

<p>Creating strongly-typed events and event handlers</p>


This quiz is an opportunity to test your knowledge on creating strongly-typed events and event handlers.

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

Quiz