The Component Lifecycle

https://reactjs.org/docs/react-component.html

Each component has several "lifecycle methods" that you can override to run code at particular times in the process.

Mounting

These methods are called in the following order when an instance of a component is being created and inserted into the DOM:

• constructor()
• static getDerivedStateFromProps()
• render()
• componentDidMount()

Updating

An update can be caused by changes to props or state. These methods are called in the following order when a component is being re-rendered.

• static getDerivedStateFromProps()
• shouldComponentUpdate()
• render()
• getSnapshotBeforeUpdate()
• componentDidUpdate()