Which statement defines idempotence?

Which statement defines idempotence?

• A. An operation is idempotent if repeated requests produce different results.
• B. An operation is idempotent if it is performed only once and never repeated.
• C. An operation is idempotent if repeated requests produce the same effect as a single request.
• D. An operation is idempotent if it changes state each time it is called.

Answer: (C)

Idempotence means repeating the same operation yields the same outcome as doing it once. The statement that repeated requests produce the same effect as a single request captures this idea directly. In practice, an idempotent operation sets or leaves a state unchanged after the first call, so subsequent identical calls don’t stack changes. For example, sending a request to set a user’s status to inactive will result in that status after the first call, and further identical requests won’t alter anything further. If an operation were to change state each time or produce a different result on each attempt, it wouldn’t be idempotent.

Idempotence means repeating the same operation yields the same outcome as doing it once. The statement that repeated requests produce the same effect as a single request captures this idea directly. In practice, an idempotent operation sets or leaves a state unchanged after the first call, so subsequent identical calls don’t stack changes. For example, sending a request to set a user’s status to inactive will result in that status after the first call, and further identical requests won’t alter anything further. If an operation were to change state each time or produce a different result on each attempt, it wouldn’t be idempotent.