250+ React Js MCQ With Online Practice Test

React.js, often simply called React, is a highly popular JavaScript library for building user interfaces. Developed and maintained by Facebook, React is renowned for its component-based architecture and the ability to efficiently update and render components when data changes. It is a foundational tool for developing modern web and mobile applications, allowing developers to create dynamic and interactive user interfaces with ease. React's vast ecosystem, including tools like React Native for mobile app development, makes it a top choice for frontend development and a key player in the world of web technologies.

Practice Test

91. What is React component composition?

Answer: Combining multiple components

92. In React, how can you include one component within another component's JSX?

Answer: By using the import statement

93. What is the primary benefit of component composition in React?

Answer: Reusability of components

94. In React, what is a higher-order component (HOC)?

Answer: A component that returns another component

95. How do you pass data from a parent component to a child component in React?

Answer: By using props

96. In React, what is the purpose of the children prop?

Answer: To render child elements

97. What is the recommended way to control the rendering of child components in React?

Answer: By using conditional rendering

98. Which React concept allows you to create reusable UI elements that accept their structure as props?

Answer: Higher-order components (HOCs)

99. In React, what is the purpose of the key prop when rendering a list of components?

Answer: To define a unique identifier

100. How can you conditionally render one component or another in React based on a condition?

Answer: By using conditional rendering in JSX
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React Js Multiple Choice Questions React Js MCQ React Js Interview Questions With Answers