Is it a must that the prop must be named as "render" for render props?

  • Yes, it is a strict requirement
  • No, it can be named anything
Render props in React are a technique for sharing code between components. A render prop is a function that a component uses to render its children, allowing the children to access the component's state or other data. The render prop can be named anything, and the name of the prop does not affect its functionality. The convention of naming the prop "render" is simply a convention and is not required by React.

What is reselect and how it works?

  • A middleware for handling asynchronous actions in Redux
  • A library for managing forms in Redux applications
  • A tool for debugging React Native applications
  • A library for optimizing Redux selectors
Reselect is a library for optimizing Redux selectors. It provides a way to create memoized selectors that only recompute when their input selectors have changed. This can help to improve performance and reduce unnecessary re-renders in React applications. Reselect works by caching the results of previous computations and only re-executing the computation if the input selectors have changed.

What is the purpose of callback function as an argument of setState()?

  • To handle errors
  • To improve performance
  • To synchronize state updates
  • To update the state asynchronously
The callback function as an argument of the setState method in React is used to update the state asynchronously. When the setState method is called, the state update may not happen immediately, which can cause issues when trying to access the updated state. The callback function is called after the state has been updated, ensuring that the updated state is available for use.

What will happen if you use props in initial state?

  • It will cause a memory leak
  • It will cause a runtime error
  • It will ignore the props
  • It will work as expected
Using props in initial state will cause the initial state to ignore the props. This is because the initial state is only set once, when the component is first created. If you want to use props to initialize state, you should set the state in the constructor instead.

Give an example of reselect usage?

  • A selector that returns the length of an array
  • A selector that filters and sorts data from the Redux store
  • A selector that computes the sum of two numbers
An example of reselect usage is a selector that filters and sorts data from the Redux store. This selector can take other selectors as input and use them to filter and sort the data before returning it. For example, you could create a selector that filters a list of items by a certain category and then sorts the results by price. This selector would only recompute when the input selectors (category and items) have changed, which can help to improve performance.

How to use React label element?

In React, you can use the standard HTML "label" element to associate a label with an input field or other form element. To do this, you can use the "for" attribute on the label element, and set it to the "id" of the input field. In JSX, you can use the "htmlFor" attribute instead of "for", because "for" is a reserved keyword in JavaScript.

How to use styles in React?

  • Use the CSS module
  • Use the className attribute
  • Use the inline-style attribute
  • Use the style attribute
In React, you can use the style attribute to apply styles to a component. The style attribute takes an object that contains CSS properties and values, similar to inline styles in HTML.

How to write comments in React?

  • By using the /* */ syntax
  • By using the // syntax
  • By using the syntax
  • By using the {/* */} syntax
In React, comments can be written using the {/* */} syntax. This syntax allows comments to be included directly in JSX code without causing syntax errors. Comments can be used to provide additional information or documentation about components, or to temporarily disable parts of the code for debugging purposes.

sWhat are HOC factory implementations?

  • Higher-order components that return a function
  • Higher-order components that return a component
  • Higher-order components that are used to create other higher-order components
HOC factory implementations are higher-order components that return a function. This function can then be used to create a new higher-order component that has a specific set of props or behavior. This can be useful for creating reusable HOCs that can be customized for specific use cases. For example, you could create a withData HOC factory that takes a data source as an argument and returns a HOC that fetches and passes data to the wrapped component.

How do you use contextType?

  • By passing the context value as a prop
  • By using the useContext() hook
  • By assigning the contextType property in the class definition
  • By creating a context consumer
The contextType property is used to consume a context value in a class component in React. To use contextType, you assign the context object to the contextType property in the class definition. This allows the component to access the context value using the this.context property. ContextType can only be used with a single context object and can only be used in class components.