Can I use web components in React application?

  • Yes, but it requires additional configuration
  • No, React does not support web components
  • Yes, web components can be used directly in React
  • Yes, but it requires using a separate library
Web components can be used in a React application, but it requires additional configuration to enable support for custom elements and shadow DOM. React components can also be wrapped in web components, allowing them to be used in non-React contexts.

What is the purpose of getDerivedStateFromError?

  • To handle errors that occur during rendering
  • To update the component's state based on the error that occurred
  • To provide additional information about the error to the user
  • To log the error to the console
The getDerivedStateFromError() method is a lifecycle method in React that is called whenever an error is thrown during rendering. Its main purpose is to update the component's state with information about the error that occurred, which can then be used to render an error message or to trigger some other action in the application.

Why are inline ref callbacks or functions not recommended?

  • They can cause memory leaks
  • They can introduce performance issues
  • They are not compatible with all browsers
  • They can interfere with the component lifecycle
Inline ref callbacks or functions are not recommended because they can cause memory leaks in your application. When using an inline ref callback, the function is recreated on each render, which can result in a buildup of references that are not properly cleaned up by the garbage collector. This can lead to memory leaks over time. It is recommended to use the createRef() API or a callback ref defined outside of the component to avoid these issues.

How do you set a default value for an uncontrolled component?

  • Use the value attribute
  • Use the defaultValue attribute
  • Use the setState() method
  • Use the props attribute
In React, uncontrolled components are form components that store their own state internally. To set a default value for an uncontrolled component, you can use the defaultValue attribute. This will set the initial value of the component when it first renders.

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.