React is the most popular front end JavaScript library today. From startups to big corporations, companies are adopting this widely used technology. Big names like Netflix, Airbnb, The New York Times, and many more are already using it on their websites and mobile applications. React’s
popularity grew mainly due to how fast React web applications perform when compared to those developed using Angular. React introduced several concepts that overcame the drawbacks of
previous front end frameworks. This article will help you get familiar with a very important concept of React, the state. React State holds the data for a component. The component, in turn, returns the data contained within the
state to the output. The state is a built-in React object that is used to contain data or information about the component. A component’s state can change over time; whenever it changes, the component re-renders. The change in state can happen as a response to user action or
system-generated events and these changes determine the behavior of the component and how it will render. class Greetings extends React.Component { state = { name: "World" }; updateName() { this.setState({ name: "Simplilearn" }); } render() { return( <div> {this.state.name} </div> ) } }
The setState() MethodState can be updated in response to event handlers, server responses, or prop changes. This is done using the setState() method. The setState() method enqueues all of the updates made to the component state and instructs React to re-render the component and its children with the updated state. Always use the setState() method to change the state object, since it will ensure that the component knows it’s been updated and calls the render() method. Now that we are familiar with the concept of a state in React, let’s have a look at how it is implemented in a React web application. class Bike extends React.Component { constructor(props) { super(props); this.state = { make: "Yamaha", model: "R15", color: "blue" }; } changeBikeColor = () => { this.setState({color: "black"}); } render() { return ( <div> <h2>My {this.state.make}</h2> <p> It is a {this.state.color} {this.state.model}. </p> <button type="button" onClick={this.changeBikeColor} >Change color</button> </div> ); } } Master the fundamentals of React for developing user interfaces like props and state with the React.js Training Course. Enroll now! State vs. PropsLet’s go through the fundamental differences between state and props:
And with that, we are now familiar with state, one of the essential concepts of React. This is one of the commonly asked topics in the ReactJS interview questions. Check out the following video tutorial to get an in-depth understanding of ReactJS state - Learn for Free! Get access to our library of over 2000+ learning videos. What are you waiting for? Get Ahead of the Curve and Master React TodayNow that you have learned one of the React’s most fundamental concepts, you may be wondering how you can obtain the skills necessary to take advantage of its rising popularity. Simplilearn offers a comprehensive React.js Training Course that will help you become career-ready upon completion. To learn more, check out our video lessons on ReactJS for beginners covering the fundamental concepts of React in greater depth. If you’re a web and mobile developer, React training will help you broaden your skills and your career horizons. |