Programming · Flashcard
When is a default parameter value evaluated?
- AOnce, when the function is defined — the same object is reused on every call
- BOn every call that omits the argument — a fresh object is built each time
- COn the first call only — later calls reuse the value cached at that point
- DLazily on first use in the body — untouched defaults are never evaluated
Why this is the answer
Defaults are evaluated once at def time and stored on the function object — the root of the mutable-default gotcha. They're not rebuilt per call (the common wrong assumption), not tied to the first call, and not lazy.
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