Learn React Js MCQs
Prepare React Js MCQs (Multiple choice Questions) for exam and job interviews.
How do you handle complex state logic?
1) Using `useState`
2) Using `useEffect`
3) Using `useReducer`
4) Using `useRef`
Answer : Option 3
What is the purpose of `useMemo`?
1) To manage state
2) To optimize rendering by memoizing a value
3) To handle side effects
4) To create refs
Answer : Option 2
What is the purpose of the `React.useState` hook?
1) To manage the component’s local state
2) To handle side effects
3) To optimize performance
4) To create refs
Answer : Option 1
How can you make a component re-render in React?
1) By changing its state or props
2) By using `useEffect`
3) By using `useMemo`
4) By using `useReducer`
Answer : Option 1
What does `React.Component` do?
1) It defines a class component
2) It defines a functional component
3) It creates a new context
4) It handles side effects
Answer : Option 1
What is a React hook?
1) A function that lets you use state and other React features
2) A way to create class components
3) A method to handle side effects
4) A way to optimize performance
Answer : Option 1
What is the correct way to pass props to a component?
1) Props can be passed using attributes
2) Props can be passed using state
3) Props can only be passed using context
4) Props can only be passed using refs
Answer : Option 1
How can you access a child component’s method?
1) Using `refs`
2) Using props
3) Using state
4) Using context
Answer : Option 1
What is the purpose of the `key` prop in React?
1) To uniquely identify elements in a list
2) To manage state
3) To handle side effects
4) To create refs
Answer : Option 1
How do you handle form submission in React?
1) Using `onSubmit` event
2) Using `onChange` event
3) Using `onClick` event
4) Using `onKeyPress` event
Answer : Option 1