How to use connect from React Redux?
- Use it as a HOC to connect a component to the Redux store
- Use it as a middleware for handling async actions
- Use it to create a new Redux store
- Use it to reset the Redux state
connect is a Higher Order Component (HOprovided by React Redux that allows you to connect a component to the Redux store. It provides the component with access to the store and allows the component to subscribe to changes in the store's state.
What is the difference between Real DOM and Virtual DOM?
- Real DOM is faster than Virtual DOM
- Virtual DOM is faster than Real DOM
- Real DOM is a physical representation of the web page, while Virtual DOM is a virtual representation
- Virtual DOM is a physical representation of the web page, while Real DOM is a virtual representation
The Real DOM is a physical representation of the web page, consisting of all the HTML elements, their attributes, and their relationships with each other. The Virtual DOM, on the other hand, is a lightweight JavaScript representation of the Real DOM. The Virtual DOM allows React to update the UI efficiently by minimizing the number of updates needed to the Real DOM.
Can I dispatch an action in reducer?
- Yes, it is a common practice
- No, it violates the principle of unidirectional data flow
No, it is not recommended to dispatch actions in a reducer function. This violates the principle of unidirectional data flow in Redux, in which actions flow in a single direction from the view to the reducer. Dispatching an action in a reducer can lead to unexpected behavior and make the application more difficult to reason about.
What is the difference between Imperative and Declarative in React?
- Imperative is more performant than declarative
- Declarative is more concise than imperative
- Imperative is easier to read than declarative
- Declarative is easier to reason about than imperative
In React, Imperative and Declarative are two different approaches to building user interfaces. Imperative programming involves giving explicit instructions on how to accomplish a task, while declarative programming involves describing what the outcome should be without specifying how to achieve it. React uses a declarative approach, which means that developers describe what the user interface should look like, and React takes care of the details of how to render it. This makes it easier to reason about and maintain complex UIs.
How to use Polymer in React?
- Use the Polymer CLI to generate a React app with Polymer components
- Use the @polymer/reactive-elements library
- Use the React Polymer bridge library
- There is no way to use Polymer in React
To use Polymer in React, you can use the @polymer/reactive-elements library. This library provides React components that wrap Polymer elements, allowing you to use them in your React applications. The @polymer/reactive-elements library also provides a way to create new React components that extend existing Polymer elements.
What are inline conditional expressions?
- Expressions that are evaluated during compilation
- Expressions that are evaluated during runtime
- Expressions that are used to conditionally render components
- Expressions that are used to set component state
Inline conditional expressions in React are expressions that are used to conditionally render components based on a certain condition. They are typically used in JSX, and are written using the ternary operator. Inline conditional expressions are a simple and effective way to conditionally render components without the need for additional logic.
Why is a component constructor called only once?
- The constructor is called for each new instance of the component
- The constructor is not needed in functional components
- The constructor is not used in React components
- The constructor is only called when the component is first created
In React, the constructor is called only once when the component is first created. This is because the constructor is used to initialize the component state and bind event handlers, and these operations only need to be performed once. After the component has been created, subsequent updates will use the "componentDidUpdate()" method to update the state and re-render the component.
What is the stable release for hooks support?
- React 15
- React 16
- React 17
React Hooks were first introduced in React 16.8, and have been a stable feature of React since React 16.8.0. React 17 is the most recent stable release of React as of September 2021.
What is the benefit of styles modules?
- Styles modules allow for dynamic styling with props
- Styles modules allow you to use CSS with React components
- Styles modules are required for server-side rendering
- Styles modules prevent CSS class naming collisions
Styles modules in React allow you to avoid CSS class naming collisions by generating unique class names at runtime. This helps prevent conflicts with other styles in the project, and allows you to use descriptive class names without worrying about naming conventions.
What is the lifecycle methods order in mounting?
- componentDidMount, componentWillMount, componentWillReceiveProps
- componentDidMount, componentWillReceiveProps, componentWillMount
- componentWillMount, componentDidMount, componentWillReceiveProps
- componentWillMount, componentWillReceiveProps, componentDidMount
The lifecycle methods for mounting a component in React are as follows: componentWillMount, render, componentDidMount. The "componentWillMount" method is called before the component is mounted to the DOM, "render" is called to render the component, and "componentDidMount" is called after the component is mounted to the DOM.