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Memo, Ref & Context Hooks interview questions

18 real Memo, Ref & Context Hooks questions from the React bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.

1. What is useMemo?

Mid
  1. A.a hook that manages state via a reducer function, suited to complex state transitions
  2. B.a hook that memoizes an expensive computed value between renders unless its dependencies change
  3. C.a hook that reads the current value of a React context without prop drilling
  4. D.a hook that memoizes a function's identity between renders unless its dependencies change
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3. Which statement is correct?

Mid
  1. A.useMemo — a hook that memoizes a function's identity between renders unless its dependencies change
  2. B.useMemo — a hook that memoizes an expensive computed value between renders unless its dependencies change
  3. C.useMemo — a hook that manages state via a reducer function, suited to complex state transitions
  4. D.useMemo — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
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4. What is useCallback?

Mid
  1. A.a hook that memoizes an expensive computed value between renders unless its dependencies change
  2. B.a hook that memoizes a function's identity between renders unless its dependencies change
  3. C.a hook returning a mutable object whose .current persists across renders without causing re-renders
  4. D.a hook that manages state via a reducer function, suited to complex state transitions
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6. Which statement is correct?

Mid
  1. A.useCallback — a hook returning a mutable object whose .current persists across renders without causing re-renders
  2. B.useCallback — a hook that manages state via a reducer function, suited to complex state transitions
  3. C.useCallback — a hook that reads the current value of a React context without prop drilling
  4. D.useCallback — a hook that memoizes a function's identity between renders unless its dependencies change
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7. What is useRef?

Mid
  1. A.a function named with a 'use' prefix that composes built-in hooks to share stateful logic
  2. B.a hook returning a mutable object whose .current persists across renders without causing re-renders
  3. C.a hook that reads the current value of a React context without prop drilling
  4. D.a hook that memoizes an expensive computed value between renders unless its dependencies change
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9. Which statement is correct?

Mid
  1. A.useRef — a hook returning a mutable object whose .current persists across renders without causing re-renders
  2. B.useRef — a hook that reads the current value of a React context without prop drilling
  3. C.useRef — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
  4. D.useRef — a hook that manages state via a reducer function, suited to complex state transitions
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10. What is useContext?

Mid
  1. A.a hook returning a mutable object whose .current persists across renders without causing re-renders
  2. B.a hook that memoizes an expensive computed value between renders unless its dependencies change
  3. C.a hook that manages state via a reducer function, suited to complex state transitions
  4. D.a hook that reads the current value of a React context without prop drilling
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12. Which statement is correct?

Mid
  1. A.useContext — a hook returning a mutable object whose .current persists across renders without causing re-renders
  2. B.useContext — a hook that manages state via a reducer function, suited to complex state transitions
  3. C.useContext — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
  4. D.useContext — a hook that reads the current value of a React context without prop drilling
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13. What is useReducer?

Mid
  1. A.a hook returning a mutable object whose .current persists across renders without causing re-renders
  2. B.a hook that memoizes an expensive computed value between renders unless its dependencies change
  3. C.a hook that manages state via a reducer function, suited to complex state transitions
  4. D.a function named with a 'use' prefix that composes built-in hooks to share stateful logic
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15. Which statement is correct?

Mid
  1. A.useReducer — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
  2. B.useReducer — a hook that manages state via a reducer function, suited to complex state transitions
  3. C.useReducer — a hook that reads the current value of a React context without prop drilling
  4. D.useReducer — a hook that memoizes an expensive computed value between renders unless its dependencies change
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16. What is Custom hook?

Mid
  1. A.a hook that reads the current value of a React context without prop drilling
  2. B.a hook that manages state via a reducer function, suited to complex state transitions
  3. C.a hook that memoizes an expensive computed value between renders unless its dependencies change
  4. D.a function named with a 'use' prefix that composes built-in hooks to share stateful logic
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18. Which statement is correct?

Mid
  1. A.Custom hook — a hook that manages state via a reducer function, suited to complex state transitions
  2. B.Custom hook — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
  3. C.Custom hook — a hook that memoizes an expensive computed value between renders unless its dependencies change
  4. D.Custom hook — a hook that reads the current value of a React context without prop drilling
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