What Is State In React JS?

State is a built-in feature in React that allows components to keep track of changes in their data. It is an object that holds information about the component’s state and can be updated based on user interactions or other events.

State and Setstate in Class Components

In class components, state is defined using the constructor method and can be modified using the setState() method. This allows for dynamic updates to the component’s data and triggers a re-render of the component with the updated information.

Here’s an example of how state and setState() are used in a class component:

“`jsx
import React, { Component } from ‘react’;

class Counter extends Component {
constructor(props) {
super(props);
this.state = {
count: 0
};
}

incrementCount = () => {
this.setState({ count: this.state.count + 1 });
}

render() {
return (

);
}
}

export default Counter;
“`

In this example, the Counter component has a state object with a count property. When the button is clicked, the incrementCount method is called, which in turn calls setState() to update the count property and trigger a re-render of the component with the new count value.

State in React allows for the creation of dynamic and interactive components that can respond to user input and other events. It is an essential concept to understand when working with React and building complex user interfaces.

Overall, state and setState() are important features in React class components that enable components to manage and update their own data, leading to a more interactive and responsive user experience.