STUDYNOTE.md

project starter

start new app:npx create-react-app 'project name' start localhost: npm start

What is state

What is class component

class component has a state, while functional component is stateless in react, we only use arrow functions in JS, we do not use function keyword.

What is props

• when we have parent and child component, we can use props to pass data from parent to child.
• App.js is Parent.js's parent component.
• to start props in class component, we need the following lines constructor(props){ super(props) }
• to start props in functional component, we need to pass props in parameter function myFunc(props){ DoThis }

event handling in react

• event handling in functional component: function keyword can be used.
• in class component: only arrow functions can be used.

CSS styling in react

• inline styling syntax

  This is Inline CSS.

• see app.js for css styling
• see second.js for component styling with a different css style sheet