What is Concurrent Rendering?
- A rendering technique for low-end devices
- A rendering technique for high-end devices
- A new feature in React 18
- A way to render multiple parts of a component tree at the same time
Concurrent Rendering is a new rendering strategy introduced in React 18 that allows multiple parts of a component tree to be rendered at the same time, without blocking the UI thread. This means that the user interface can remain responsive while React is rendering updates. Concurrent Rendering is particularly useful for large and complex applications that need to maintain high performance.
How to pass a parameter to an event handler or callback?
- Using an arrow function
- Using the bind method
- Using the event object
- Using the setState method
A parameter can be passed to an event handler or callback in React by using an arrow function. The arrow function takes the event as a parameter, along with any additional parameters that need to be passed. This approach ensures that the event object is properly handled and that the correct parameters are passed to the event handler or callback.
How to update a component every second?
- Use the setInterval() function in the componentDidMount() method
- Use the setInterval() function in the constructor method
- Use the setTimeout() function in the componentDidUpdate() method
- Use the setTimeout() function in the render() method
In React, you can update a component every second by using the "setInterval()" function in the "componentDidMount()" lifecycle method. This will create a timer that updates the component state every second, causing the component to re-render with the new state values. For example: componentDidMount() { this.timerID = setInterval(() => this.tick(), 1000); }.
How to reset state in Redux?
- Dispatch a RESET action
- Modify the state directly
- Use the combineReducers function
To reset the state in Redux, you can dispatch a RESET action to the Redux store. This action can be handled by a reducer function that returns the initial state of the application. This allows you to reset the application state to its initial values.
How do you access the imperative API of web components?
- Use the refs API in React
- Use the useEffect() hook in React
- Use the setState() method in React
- Use the createContext() API in React
In React, you can use the refs API to access the imperative API of web components. By using refs, you can reference a web component and then access its imperative API methods and properties.
What is context?
- A JavaScript library for data visualization
- A global object used to store application state
- A way to pass data down to child components without using props
- A way to pass data up to parent components without using props
Context is a way to pass data down to child components without using props. It is useful for data that needs to be accessed by many components at different levels of the component hierarchy. Context provides a way to avoid the "prop drilling" problem, where props need to be passed down through many layers of components.
How to do logging in React Native?
- Use the console.log() function
- Use the alert() function
- Use the debugger statement
- All of the above
To do logging in React Native, you can use the console.log() function, which writes messages to the console in the same way as in a web browser. You can also use other console functions, such as console.warn() and console.error(), to log warning and error messages.
Why React tab is not showing up in DevTools?
- The React DevTools extension is not installed
- The React app is not running in development mode
- There is a conflict with other browser extensions
- The React app is not using React version 16 or higher
If the React tab is not showing up in DevTools, it may be because the React app is not using React version 16 or higher. The React tab was introduced in version 16, so if you are using an earlier version of React, it will not be available in DevTools. You can check the React version in your app by looking at the package.json file or by running the command 'npm ls react'.
What is Flux?
- A testing framework for React
- A database management system
- A design pattern for managing state in React applications
- A CSS preprocessor
Flux is a design pattern for managing state in React applications. It was developed by Facebook and is often used in combination with React. Flux emphasizes a unidirectional data flow, in which data flows in a single direction through the application. This helps prevent issues with data inconsistency and makes it easier to manage state in large applications.
What is the difference between React Native and React?
- React Native is a mobile app development framework, while React is a web development framework
- React Native is a JavaScript library, while React is a markup language
- React Native is used for developing web applications, while React is used for developing mobile applications
- React Native and React are the same thing
React Native is a mobile app development framework that allows developers to build mobile applications using JavaScript and React. It is a separate technology from React, which is a JavaScript library for building user interfaces on the web. While both React and React Native use a similar programming model, they have different APIs and are optimized for different platforms.