Throughout the course we will be using Yarn, however using NPM or Yarn is a personal choice. You can use this as a reference guide for the two different commands you can use. Don't worry if you are not sure of the below commands as we will explore them throughout the course:
Install dependencies from package.json: npm install == yarn
Install a package and add to package.json: npm install package --save == yarn add package
Install a devDependency to package.json: npm install package --save-dev == yarn add package --dev
Remove a dependency from package.json: npm uninstall package --save == yarn remove package
Upgrade a package to its latest version: npm update --save == yarn upgrade
Install a package globally: npm install package -g == yarn global add package
Class Components
Lifecycle of Components
Each component in React has a lifecycle which you can monitor and manipulate during its three main phases. The three phases are: Mounting, Updating, and Unmounting.
Mounting - Mounting means putting elements into the DOM.
React has four built-in methods that gets called, in this order, whrn mounting a component : 1. contructor() 2. getDerivedStateFromProps() 3. render() 4. componentDidMount()
The render() method is required and will always be called, the others are optional and will be called if you define them.
1. Contructor()
The constructor() method is called before anything else, when the component is initiated, and it is the natural place to set up the initial state and other initial values. The constructor() method is called with the props, as arguments, and you should always start by calling the super(props) before anything else, this will initiate the parent's constructor method and allows the component to inherit methods from its parent (React.Component).