18 Memo, Ref & Context Hooks questions from the React bank, written for Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd.
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A.a hook that manages state via a reducer function, suited to complex state transitions
B.a hook that memoizes an expensive computed value between renders unless its dependencies change
C.a hook that reads the current value of a React context without prop drilling
D.a hook that memoizes a function's identity between renders unless its dependencies change
Answer + AI explanation with Pro
2. Which term means: "a hook that memoizes an expensive computed value between renders unless its dependencies change"?
Mid
A.useRef
B.useContext
C.useMemo
D.useReducer
Answer + AI explanation with Pro
3. Which statement is correct?
Mid
A.useMemo — a hook that memoizes a function's identity between renders unless its dependencies change
B.useMemo — a hook that memoizes an expensive computed value between renders unless its dependencies change
C.useMemo — a hook that manages state via a reducer function, suited to complex state transitions
D.useMemo — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
Answer + AI explanation with Pro
4. What is useCallback?
Mid
A.a hook that memoizes an expensive computed value between renders unless its dependencies change
B.a hook that memoizes a function's identity between renders unless its dependencies change
C.a hook returning a mutable object whose .current persists across renders without causing re-renders
D.a hook that manages state via a reducer function, suited to complex state transitions
Answer + AI explanation with Pro
5. Which term means: "a hook that memoizes a function's identity between renders unless its dependencies change"?
Mid
A.Custom hook
B.useReducer
C.useRef
D.useCallback
Answer + AI explanation with Pro
6. Which statement is correct?
Mid
A.useCallback — a hook returning a mutable object whose .current persists across renders without causing re-renders
B.useCallback — a hook that manages state via a reducer function, suited to complex state transitions
C.useCallback — a hook that reads the current value of a React context without prop drilling
D.useCallback — a hook that memoizes a function's identity between renders unless its dependencies change
Answer + AI explanation with Pro
7. What is useRef?
Mid
A.a function named with a 'use' prefix that composes built-in hooks to share stateful logic
B.a hook returning a mutable object whose .current persists across renders without causing re-renders
C.a hook that reads the current value of a React context without prop drilling
D.a hook that memoizes an expensive computed value between renders unless its dependencies change
Answer + AI explanation with Pro
8. Which term means: "a hook returning a mutable object whose .current persists across renders without causing re-renders"?
Mid
A.useContext
B.useReducer
C.useRef
D.useCallback
Answer + AI explanation with Pro
9. Which statement is correct?
Mid
A.useRef — a hook returning a mutable object whose .current persists across renders without causing re-renders
B.useRef — a hook that reads the current value of a React context without prop drilling
C.useRef — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
D.useRef — a hook that manages state via a reducer function, suited to complex state transitions
Answer + AI explanation with Pro
10. What is useContext?
Mid
A.a hook returning a mutable object whose .current persists across renders without causing re-renders
B.a hook that memoizes an expensive computed value between renders unless its dependencies change
C.a hook that manages state via a reducer function, suited to complex state transitions
D.a hook that reads the current value of a React context without prop drilling
Answer + AI explanation with Pro
11. Which term means: "a hook that reads the current value of a React context without prop drilling"?
Mid
A.Custom hook
B.useMemo
C.useContext
D.useReducer
Answer + AI explanation with Pro
12. Which statement is correct?
Mid
A.useContext — a hook returning a mutable object whose .current persists across renders without causing re-renders
B.useContext — a hook that manages state via a reducer function, suited to complex state transitions
C.useContext — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
D.useContext — a hook that reads the current value of a React context without prop drilling
Answer + AI explanation with Pro
13. What is useReducer?
Mid
A.a hook returning a mutable object whose .current persists across renders without causing re-renders
B.a hook that memoizes an expensive computed value between renders unless its dependencies change
C.a hook that manages state via a reducer function, suited to complex state transitions
D.a function named with a 'use' prefix that composes built-in hooks to share stateful logic
Answer + AI explanation with Pro
14. Which term means: "a hook that manages state via a reducer function, suited to complex state transitions"?
Mid
A.Custom hook
B.useContext
C.useCallback
D.useReducer
Answer + AI explanation with Pro
15. Which statement is correct?
Mid
A.useReducer — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
B.useReducer — a hook that manages state via a reducer function, suited to complex state transitions
C.useReducer — a hook that reads the current value of a React context without prop drilling
D.useReducer — a hook that memoizes an expensive computed value between renders unless its dependencies change
Answer + AI explanation with Pro
16. What is Custom hook?
Mid
A.a hook that reads the current value of a React context without prop drilling
B.a hook that manages state via a reducer function, suited to complex state transitions
C.a hook that memoizes an expensive computed value between renders unless its dependencies change
D.a function named with a 'use' prefix that composes built-in hooks to share stateful logic
Answer + AI explanation with Pro
17. Which term means: "a function named with a 'use' prefix that composes built-in hooks to share stateful logic"?
Mid
A.useRef
B.useMemo
C.useContext
D.Custom hook
Answer + AI explanation with Pro
18. Which statement is correct?
Mid
A.Custom hook — a hook that manages state via a reducer function, suited to complex state transitions
B.Custom hook — a function named with a 'use' prefix that composes built-in hooks to share stateful logic
C.Custom hook — a hook that memoizes an expensive computed value between renders unless its dependencies change
D.Custom hook — a hook that reads the current value of a React context without prop drilling
Answer + AI explanation with Pro
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