States & Props in React

statesAndProps.md

What are they ?

States

• A value that changes depending on a user's actions is called state in React.
• State can be updated.
• Prevent re-rendering
• Three steps to use state:
  • Define: State is created using an object in the constructor. constructor(props) { super(props); this.state = {name: 'Ken the Ninja'}; }
  • Display: Since this.state is an object, you can get the value of any property by writing code like this.state.propertyName
  • Update: With the code this.setState({propertyName: valueToUpdate}), the value of state for the specified property changes. setState() method is used.

Props

• In React, you can pass props, or properties, to child components.