What Is the State in React? A Simple Guide for Beginners

In today's era, React is one of the most famous frontend JavaScript libraries. Ranging from startups to big companies, everyone is adopting them for a big purpose. Various companies like. Netflix, Airbnb, and The New York Times are already implementing this on their website and other mobile applications. The popularity of React has increased due to how fast this React application performs compared to developing this using Angular. Various frameworks are used that just overcome the drawbacks of other frontend frameworks.

What Is ‘State’ in ReactJS?

This ‘state’ is one of the built-in React objects that is used to contain data as well as other information about a particular component. Over time component's state can change, and whenever changes are made, the component re-renders. System-generated events or user responses to a particular action can be the reason for this change.

What Is ‘State’ in ReactJS?The setState() MethodState vs. PropsGet Ahead of the Curve and Master React Today

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.

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What Is ‘State’ in ReactJS?

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 state change 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. ;

updateName() {

this.setState({ name: "Simplilearn" });

}

render() {

return(

{this.state.name}

)

}

}

• Based on user action or network changes, one can modify the state easily.

• Every time this state of the object changes, React will re-render components to the browser.

• This state of object is simply initialised in the constructor.

• Multiple properties can get easily stressed by this state of the object

• Use this setState() to change the state of the object.

• setState() is a function that will perform a shallow merge between the new as well. as the previous state.

The setState() Method

In response to the event handlers, server responses, or prop changes state can be easily changed. Always use only the setState() method that will state the object. This just makes sure that the component knows that it has been updated and even calls the render () method.

As we are familiar now with React, let's see how it is implemented in a React web application.

Class Bike extends React. ;

}

changeBikeColor = () => {

this.setState({color: "black"});

}

render() {

return (

My {this.state.make}

It is a {this.state.color}

{this.state.model}.

Change color

);

}

}

Difference between State and Props

Parameters

State

Props

Use Cases

State is mostly used when you want to store data of a component that has to be rendered to a particular view.

Props are simply used to pass your data and event handlers to the child components.

Mutability

State simply holds data that you can change over time.

Props are simply immutable; once set, you cannot make any changes.

Updation

Event handlers will mostly update the state

This parent component will simply set props for the children components.

Component

Use state only in class components. While props can be used in both functional as well as class components.

Here are some listed advantages of using the state in React

• Dynamism in UI rendering - React will automatically re-render components whenever the state changes. They make sure that UI will always reflect their current state.

• Local scope - We can see that component-level State will not interfere with other components unless they are shared. So, unnecessary coupling can be avoided to a great extent.

• Interactivity - State just helps in enabling interactivity, like form inputs, toggles, and modals. Without this, React components would be static and also unresponsive to the user's input.

• Hook integration - The useState hook will provide an easy route to manage the state of all functional components. They are even more concise and also easier to test compared to testing class components.

• Predictable state transitions - With a controlled set of states and updated flow. This is done especially using useReducer. Developers can now predict how and when the state will change.

When advantages are there, then some disadvantages also come along with that :

• Prop drilling - While using multiple components having a single state or data requires you to pass through multiple levels. This will lead to messy and even hard-to-maintain code.

• Performance overheads - Frequent state updates can lead to excessive re-rendering. You can do this, particularly in deploying nested components. You can see performance bottlenecks because of this.

• Boilerplate code - For managing state properly, writing extra code for handlers and updates is also required. Also, this can lead to components getting bloated.

• Asynchronous nature - React will batch state updates in a quite asynchronous manner. All this will lead to confusing behaviour if we assume that state updates immediately.

• Complex state logic - As your app grows, the state logic will become quite hard to manage. Example - Imagine you are dealing with multiple pieces of data that require complicated update-related logic or even some external state management tools.

Some of the practical applications of React are mentioned below ;

• Form handling - This kind of React state is mostly used to control inputs to the form and also its variations.

Example

const [email, setEmail] = useState("");

setEmail(e.target.value)} />

You can also validate and submit data here by using the state.

• Authentication-related flow - This will help in tracking a state to know whether a user has logged in.

const [isAuthenticated, setIsAuthenticated] = useState(false);

Based on the above condition, you can render user dashboards or even simple login forms.

• Toggles and UI elements - Ranging from drop-down to modals and also sidebars, so the state will simply control whether these elements are open or closed.

const [isModalOpen, setIsModalOpen] = useState(false);

• Fetching API related data - State is most commonly used to store as well as display API response data.

useEffect(() => {

fetch('/api/data')

.then(res => res.json())

.then(data => setData(data));

}, []);

• Pagination - When you are simply paginating through all the items, then the state just helps to track the current page's total items and also items per page.

const [currentPage, setCurrentPage] = useState(1);

• Game States - In different interactive applications like games, Reactstate can handle variations like score, player health, or even level progression.

const [score, setScore] = useState(0);

• Multi-step forms - You can use state to track the current step and also store user input across all sets of steps

const [step, setStep] = useState(1);

• Live search filtering - State is often an essential tool for dynamic filtering or other live search features.

const [searchQuery, setSearchQuery] = useState("");

• Theme switching - You can easily toggle between light and dark modes by using this Boolean state.

const [darkMode, setDarkMode] = useState(false);

• Real-time chat applications - State often holds message history and will update as new messages arrive.

const [messages, setMessages] = useState([]);

Best practices that one should use while implementing state in React

• Keep your state quite minimal - Never share derived data in state anytime. Just computer it whenever you need it.

• Lift the state - Move your state to the nearest common ancestor when multiple components need to access that data.

• Use only controlled elements - Always try to bind form inputs to state. Do this for better control and validation purposes.

• Avoid Deep nesting - Try to use custom hooks or even separate logic into smaller components. Do all this for better readability.

Conclusion :

State present in React plays an important fundamental role. They do this in building dynamic and interactive user interfaces. On the other hand, clear advantages like modular logic, responsive rendering, and dynamic interactivity are observed. Challenges like performance issues and also prop-drilling are posed in large applications.

When it comes to smaller or mid-sized applications, managing state at the component level usually does the trick. However, as these applications grow, it becomes essential to adopt more robust state management strategies. That's when developers often look to external libraries to help manage shared state across various components smoothly. These concepts are typically covered in foundational courses, like a Full stack developer course in delhi which attracts learners from cities like Kanpur, Ludhiana, Moradabad, Noida, and beyond. In today's tech landscape, mastering the art of building scalable apps is an invaluable skill.

By understanding when and how to use this state effectively, one can significantly improve the quality as well as maintainability of React operations. Enroll in the right course, like a Data Science course in Noida, and you can also connect with us for any further queries. Acquire all the training relevant to current needs. Select the ideal platform to advance your career.

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