React components always have to call ________ for constructors to be set up properly.

React components always have to call ________ for constructors to be set up properly.

• A. super(props);
• B. this.state = { }
• C. React.createClass({})
• D. Component.initState()

Answer: (A)

When you write a React class component, the constructor has to start by calling the base class constructor so the instance is set up correctly and props are initialized. Using super(props) calls the React.Component constructor with the component’s props, which lets you access this and this.props inside the constructor safely and ensures the component infrastructure is ready to use. Setting the initial state with this.state = { } is something you typically do inside the constructor after super has been called, but it does not perform the essential initialization of the base class itself. React.createClass({}) is an older pattern that doesn’t use ES6 class constructors in the same way, so it doesn’t apply to the same setup. Component.initState() isn’t a real React API. So the one that guarantees proper constructor setup is super(props).

When you write a React class component, the constructor has to start by calling the base class constructor so the instance is set up correctly and props are initialized. Using super(props) calls the React.Component constructor with the component’s props, which lets you access this and this.props inside the constructor safely and ensures the component infrastructure is ready to use.

Setting the initial state with this.state = { } is something you typically do inside the constructor after super has been called, but it does not perform the essential initialization of the base class itself. React.createClass({}) is an older pattern that doesn’t use ES6 class constructors in the same way, so it doesn’t apply to the same setup. Component.initState() isn’t a real React API. So the one that guarantees proper constructor setup is super(props).