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React Js MCQs MCQs: 536 Questions & Answers in Programming

536 React Js MCQs MCQs in Programming with answers & explanations. Practice objective questions for competitive exams, interviews & self-assessment — free on… Use the answer toggle below to show or hide all solutions, tap an option to check one question, or open a question for its own page.

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React Js MCQs MCQs: 536 Questions & Answers in Programming

What is the purpose of the useState hook in React?

Which method is used to render React components to the DOM?

In React, what is JSX?

Which hook is used to perform side effects in functional components?

What is the virtual DOM in React?

What is the default state of a new useState variable?

How do you prevent a component from re-rendering in React?

Which method is used to pass data from parent to child in React?

Which hook allows sharing logic between components in React?

What does the key prop do in React lists?

Which lifecycle method is invoked immediately after a component is mounted?

Which hook is used to store a mutable value that does not cause re-render?

Which company developed React?

What is the correct syntax to handle an event in React?

What does the useEffect hook return?

What is the second argument of useEffect used for?

Which of the following is true about React keys?

What will happen if you change the state directly without setState or useState?

How can props be made optional in a functional component?

What does the 'key' prop help React identify?

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