Make React Function Components Stateful with useState

For function components, the useState hook is how you make your component stateful. This replaces the previous convention from class components where values were stored in a this.state object and manipulated using this.setState().

The hook returns an array with two values: the state value your are storing and a function that allows you to updated it. When instantiating the hook, the initial state value is determined by whatever value you pass it.

const [value, setValue] = useState(null)