12 Idempotency & Safety questions from the REST API 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 method where each repeated call may produce additional side effects, such as creating a new record every time
B.a method that is read-only by contract and must not cause any change to server resource state
C.an operation whose repeated execution produces the same server state as a single execution
D.a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
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2. Which term means: "an operation whose repeated execution produces the same server state as a single execution"?
Mid
A.Safe Method
B.Idempotency-Key Header
C.Non-Idempotent Method
D.Idempotent Operation
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3. Which statement is correct?
Mid
A.Idempotent Operation — a method where each repeated call may produce additional side effects, such as creating a new record every time
B.Idempotent Operation — a method that is read-only by contract and must not cause any change to server resource state
C.Idempotent Operation — an operation whose repeated execution produces the same server state as a single execution
D.Idempotent Operation — a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
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4. What is Safe Method?
Mid
A.a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
B.an operation whose repeated execution produces the same server state as a single execution
C.a method where each repeated call may produce additional side effects, such as creating a new record every time
D.a method that is read-only by contract and must not cause any change to server resource state
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5. Which term means: "a method that is read-only by contract and must not cause any change to server resource state"?
Mid
A.Idempotent Operation
B.Non-Idempotent Method
C.Safe Method
D.Idempotency-Key Header
Answer + AI explanation with Pro
6. Which statement is correct?
Mid
A.Safe Method — a method that is read-only by contract and must not cause any change to server resource state
B.Safe Method — a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
C.Safe Method — an operation whose repeated execution produces the same server state as a single execution
D.Safe Method — a method where each repeated call may produce additional side effects, such as creating a new record every time
Answer + AI explanation with Pro
7. What is Idempotency-Key Header?
Senior
A.a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
B.a method where each repeated call may produce additional side effects, such as creating a new record every time
C.a method that is read-only by contract and must not cause any change to server resource state
D.an operation whose repeated execution produces the same server state as a single execution
Answer + AI explanation with Pro
8. Which term means: "a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once"?
Senior
A.Non-Idempotent Method
B.Idempotent Operation
C.Safe Method
D.Idempotency-Key Header
Answer + AI explanation with Pro
9. Which statement is correct?
Senior
A.Idempotency-Key Header — a method that is read-only by contract and must not cause any change to server resource state
B.Idempotency-Key Header — a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
C.Idempotency-Key Header — a method where each repeated call may produce additional side effects, such as creating a new record every time
D.Idempotency-Key Header — an operation whose repeated execution produces the same server state as a single execution
Answer + AI explanation with Pro
10. What is Non-Idempotent Method?
Mid
A.a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
B.an operation whose repeated execution produces the same server state as a single execution
C.a method that is read-only by contract and must not cause any change to server resource state
D.a method where each repeated call may produce additional side effects, such as creating a new record every time
Answer + AI explanation with Pro
11. Which term means: "a method where each repeated call may produce additional side effects, such as creating a new record every time"?
Mid
A.Non-Idempotent Method
B.Safe Method
C.Idempotency-Key Header
D.Idempotent Operation
Answer + AI explanation with Pro
12. Which statement is correct?
Mid
A.Non-Idempotent Method — an operation whose repeated execution produces the same server state as a single execution
B.Non-Idempotent Method — a unique client-supplied token that lets a server detect and de-duplicate a retried unsafe request so it executes only once
C.Non-Idempotent Method — a method that is read-only by contract and must not cause any change to server resource state
D.Non-Idempotent Method — a method where each repeated call may produce additional side effects, such as creating a new record every time
Answer + AI explanation with Pro
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