React Lifecycle

1. constructor
   One-time setup, assignments.Do not do data-loading inside the constructor, instead do it in componentDidMount.
2. render
   Return JSX, nothing else!
3. componentDidMount
   Place for data-loading, api requests etc.
4. componentDidUpdate
   Place to do more data-loading when state/props change. Render-method will be called just before this method.
5. componentWillUnmount
   Place for cleanup

Rarely used lifecycle methods:

shouldComponentUpdate

getDerivedStateFromProps

getSnapshosBeforeUpdate