example for react component lifecycle methods

Example 1: lifecycle methods react

Every component in React goes through a lifecycle of events. I like to think of them as going through a cycle of birth, growth, and death.

Mounting – Birth of your component
Update – Growth of your component
Unmount – Death of your component

Example 2: what is react mounting

React has four built-in methods that gets called, 
  in this order, when mounting a component:

constructor()
getDerivedStateFromProps()
render()
componentDidMount()
The render() method is required and will always be called, the 
others are optional and will be called if you define them.