Hey, everyone, welcome to a new post into React Js Series. Today, we learn all about React State I suggest you read the previous videos on the React Js components and props to get a better understanding of the state.
What exactly is a state in React Js
So let’s begin and learn what exactly is a state in React Js.
- Typically a state is an object that stores the values of properties belonging to a component. Now, these values can change over a period of time, either via user interactions or network changes and state helps facilitate this functionality.
- Every time the state changes, React Js re-renders the Component to the browser, the state is initialized in the constructor.
- A state can also store multiple properties. A method called setState() is used to update the value of the state object
- This function performs a shallow march on the new and the previous state convention to be a shallow merge and shows that the previous state values are overridden by the new state values.
What is the difference between state and props?
In our previous post, we learned about props, and although props and state dictate and control the behavior of a component. They have significant differences. So let’s go ahead and read the comparison between the two.
- Firstly, props in a Component are used to pass data and event handler to its children. While state, on the other hand, is used to store the data that has to be rendered on the webpage.
- Props are immutable, one set by the parent they cannot be changed. state holds volatile data and can be changed over time.
- Props can be used in functional and class Components. While state is restricted to class Components.
- Props are set by the parent competent for the child competent , while a state is generally updated by event handlers.
Now that we’ve learned all about state, let’s go ahead and build an application to see the working of state. So in my code editor that is VS Code, I’ve created a application let say “My App”.
here in my source folder, I have my app.js
import logo from './logo.svg'; import './App.css'; function App() { return ( <div> <h1>React Js Tutorial</h1> </div> ); } export default App;
So let’s create a class component say Myclasscomp.js .Let’s display a message “Hello Student, welcome to React Js Tutorial”.
import React, { Component } from "react"; class Myclasscomp extends Component { render() { return <h2>Hello Student,welcome to React Js Tutorial </h2> } } export default Myclasscomp;
Let’s follow the JSX conventions and enclose all the HTML tag within the <div> tag.
import React, { Component } from "react"; class Myclasscomp extends Component { render() { return <div> <h2>Hello Student,welcome to React Js Tutorial</h2> </div> } } export default Myclasscomp;
To give you an insight into what we’re doing.
I’m going to make use of a button ,Every time the user clicks on the button, the value gets incremented. So for this, I’m going to use a variable count and I’m going to use the concept of states. So let’s go ahead and define our variable count and initialize it to zero.
And as mentioned earlier, we initialize the state object in a constructor. Now, in the state object, we initialize a property.
let’s define the count variable, in the render method so every time we click on a button, the count value has to get incremented by 1.
so we make use of an event called onclick. So every time the button gets clicked, incrementcount method is called.
import React, { Component } from "react"; class Mycounter extends Component { constructor(props) { super(props); this.state = { counter: 0, }; } incrementcount = () => { this.setState({ counter : this.state.counter + 1 } )} render() { const { counter } = this.state; return <span><button onClick={this.incrementcount}>Touch Me-{counter} times</button></span> } } export default Mycounter;
and let’s see the browser.
Now a setstate can be updated in response to even handler and server responses or props changes. Now all the updates can be done using the setstate() method. This is a general trend that’s used by the method.
- The setState() method conventionally enqueues all the updates made to the components state and instructs react to re-render the component and its children with the updated state.
Thanks for reading
The post State ,State vs Props and SetState In ReactJS appeared first on Software Development | Programming Tutorials.
Read More Articles
- Can we pass setState as props from one component to other and change parent state from child component in React?
- Reactjs - Setting State from props using setState in child component
- ReactJs - Hide state and props
- How to set state and props on a single click event in reactjs
- How to create array from state value and setstate after removing duplicates in reactjs
- How to assign a value to state and use setState in ReactJs with Typescript
- Problem when pass data in ReactJS with props and state
- ReactJS - Difference between generates a unique id via default props and state
- ReactJS - passing data between state and props
- setState not updating state even with callback and handleFunction - ReactJs
- setstate object:{array:[]} in reactjs how could i add the **key and value inside the array which is in the state object**?
- ReactJS Multiple Input problem setState and state
- ReactJs - Passing function as props to setState - Which component's state will be updated?
- calculation and changing state inside setstate in reactjs
- relation between reactjs ,setState, Interface props and Interface state with respect to typescript , how can I use setState?
- ReactJS and Typescript - Children components : get children props and refresh children when parent state changed
- ReactJS - Calling setState inside for loop, updating the state and displaying the result
- What is the difference between state and props in React?
- How to set React component state and props from browser
- ReactJS State and Local Variable
- How can I ensure a reactjs state is updated, and then call a function?
- static getDerivedStateFromProps that requires previous props and state callback?
- ReactJS - What is difference between component state and class variable?
- Why can't I access state and props inside event handler
- ReactJS - Need to click twice to set State and run function
- Cannot update during an existing state transition (such as within `render`). Render methods should be a pure function of props and state. in Index.js
- Render methods should be a pure function of props and state
- Using an input field with onBlur and a value from state blocks input in Reactjs JSX?
- ReactJS state not updated In setState callback
- ReactJS - How to properly initialize state from props which is populated by fetching data?
- React-table events
- ReactJS: return an alert after fetch
- How to generate a unique id automatically for the data that is posted to an API server using axios library in redux
- Cross Domain Cookie Golang ReactJs
- State not updated after successful AJAX request
- Passing an Image in Material-UI Data-Grid Table
- Control Arduino using Express JS server and Johnny-Five
- How can I filter through api data and print name to console?
- On clicking on close button of page i want to clear all selectbox value
- How to create a simple react app in one file?
- Google Analytics using React Web / Cordova
- React router page redirect not correctly?
- React not able to dynamically render correct component
- TypeError: Object(...) is not a function Redux Store
- Node-fetch not working with Electron 11, error resp.body.pipe is not a function
- How to 'justify-content: center' for MUI Pagination?
- How to extract text without HTML Entities encoding from React ContentEditable?
- Conditional Check of Props Not Working In Styled-System
- Best way to implement edit functionality in my react component
- Setting authorization header in axios
- I need to execute a function that will update the state right after using setState hook, but state inside function is empty?
- Using react-form to POST to an API?
- React Js Handling event button on a column to get row using onClick
- Update password Only After Conditional is Met in NodeJS and ExpressJS
- How to type a custom pilet api?
- React build fails when sass uses calc and var together
- Custom IconComponent in MuiSelect
- How can I have a line break display when displaying a string?
- Is there a way to infer the types of a specific value from an interface passed as a generic?
- react native custom fonts
- Typescript error - No overload matches this call
- Multiple export with dot notation
- How to set image url in ReactJS
- If I want to use a javascript library like AOS in React, HOW?
- How to correct CSS differences for different OS in Semantic UI React? I am having issues with Form.Select in Semantic UI React
- Partial string matching in react
- nginx not passing request to node server, if trailing slash is missing in the url
- Saving to LocalStorage Array not updating correctly React
- ReactJS: How to trim label when it is a long text in material ui autocomplete
- React Big Calendar (w/Typescript) not showing events
- Do I need componentWillReceiveProps and replaceProps when using ReactJS + Redux?
- Testing useContext() with react-testing-library
- Issue importing an interface from ReactQuill namespace
- React-native <Text> not wrapped in inner flex
- Server-side rendering with ReactDOM.hydrate
- SetTimeout runs twice, only if the component is reconstructed
- React Asynchronous nested data fetching
- Reactjs nested routes is not redirect to child screen
- Why we need toJSON when comparing to two components equality?
- Is secure to ignore the missing dependencies es-lint warning on react hooks?
- useEffect() to many re-renders on pagination
- Endless promise loop when trying to fetch CSV data with JavaScript
- Why is my state null in my JavaScript program?
- How to redirect to login page on click of logout in react
- React hook rendering an extra time
- Error: Cannot find module '/app/react-web/react-scripts'
- React - Change in one object reflects on another even though its not modified
- Redux Form won't allow Initialize Form state values to be edited
- Electron app on Mac OSX, input for file selection
- React - Unhandled Error Event on react.render()
- A Gatsby page is not getting created by gatsby at all no matter what I do it seems
- How to improve test of react component with jest?
- How can I get the current state of element in react for rendering progress bar?
- React - Make Child component shrink when parent component shrinks
- How do you pull a list of images from firebase storage?
- React JS one way data flow confusion
- Invoking epics from within other epics
- Authentication React Redux Application
- Foreach promise all array issue
- In React, is it a good practise to return null if props is empty
- Reading environmental variables set in configmap of kubernetes pod from react application?
- react: Initial state value is undefined
- how to compare the query value from url to id using react?
- react state not working as it is supposed
- Debugging Javascript/ReactJS errors
- React: Why isn't my context value updated?
- Why all datepicker values become null when I change one of this?
- how can I use svg as background image in react?
- React JS and TypeError
- How to re-use type in React & TS application
- .filter function "is not a function" error
- How to pass an async object to a props in react?
- React Router V6 - Redirect inside Route Component
- React doesn't keep or send cookies to Node?
- Setting state not working after the first API call in react
- setState of an object - React Native
- Pass function inside string literal to other component
- reactStringReplace: trouble formatting bold/italic/underline text with capture group regex
- Embedding SVG into ReactJS
- TouchableHighlight won't accept press events while keyboard is open
- CSSTransition does not work. V2 react-transition-group
- Send a JSON through Django REST Framework
- Integrate firebase push notification - React Js web App
- How to align Card.Section components in MS Fluent UI?
- Extending a React Styled Component
- Passing data between Router Components in React
- How to clear interval function of one component from another?
- React: Returning iterated list from a stateless component
- Unable to spread an array inside a template literal
- Vertical alignment of text in a button with icon is not correct
- Npm start problem while installing react, and how to fix it?
- How can I pass values or fields from one page to another page in ReactJS?
- Error on archiving react native app in Xcode - Multiple commands produce 'libyoga.a'
- How to create a typical country/province (or state) dependency dropdowns with react-jsonschema-forms?
- React Loading Msg
- React input binding to state vs local variable
- Removing item in a todo list in react
- Recursive function not terminating even when break condition is met - JavaScript
- Recommended way to have drawer resizable?
- Change navigation styles depending on current path in Gatsby.js
- Using scalajs Diode and an ApplicationCircuit with a handler defined for a Posts (sequence), can I somehow map it to a ModelProxy[Post] individual?
- react bootstrap table show empty row
- How to get a background frosted glass effect without using background image
- Issue converting js to react component
- Update query timing out after 10 seconds despite successfully submitting in React app
- Is there a way to change the clicked color of the Chip
- Refactor a React component from function to ES6 class
- Graphql Hasura Update if the field is not null
- Why is my Enzyme test failing?
- how to shift element on click visible section in react js?
- React Render Components with Array.map auto scrolls down
- props value is populating only after second click of button
- Tell store to update without an actual data change
- Expect mocked library function to have been called
- How do I change a basic counter in react so that multiple copies all maintain the same value?
- Change value displayed to User in Slider
- Saga is being called multiple times
- ReactJS - response in async call
- Disable Button when clicked in React
- babelify transformation on JSX for React element failing
- I can't consume a JSON file
- React autoFocus sets cursor to beginning of input value
- Firestore long get request
- What's the fastest way to mutate a single object property inside a large array of objects?
- How can you pass props and use HOC with React context
- How can I access the closest <Route>'s match inside children?
- Conditionally Rendering Components From An Array of Components
- Losing JWT token after browser refresh
- How to route to a file in a folder with React Router?
- React re-renders entire function when state changes
- Dropdown not picking items from the options list
- Line 0: Parsing error: Cannot read property 'map' of undefined" - TypeScript Custom Hook
- Remove object by id from array in React hooks state
- How to extend(inherit) a global CSS class from within a styled-components
- React: Axios response loading on Console but not in DOM
- React Router url with params
- Using ReactType with JSX
- Why is the span element rendered by the Text component from the Grommet library, able to get margin-top?
- React Hook useCallback has missing dependencies: 'params' and 'posts'. You can also do a functional update 'setPosts(p => ...)
- React : retrieve the state of a child component
- Exporting component using i18n's useTranslation and redux's connect HOCs
- How to redirect a link using History to a page
- Master Check Box in AG Grid on any column
- 'Object is possibly Undefined' error on a non-object variable in React-Typescript
- How can i send this login request each minute?
- Accessing event trigger button onclick function
- How to clear all filters in react-table
- How to edit object (todo) in array? (reactjs)
- How to configure Ckeditor Toolbar in React JS?
- Calling Child Components Functions from Parent Components
- reducer is not a function
- How to return component in form Reactjs?
- How can I clear the state in React.js?
- How to store response data from Axios to a variable in React Functional Component?
- why do i get the Error Module not found: Can't resolve 'redux'
- How to add and remove table rows Dynamically in React.js
- Google Cloud speech with React Native
- How to change local state without changing global state
- How to handle error returning from a graphql backend on react admin?
- How to use a react component as a function?