السؤال 79

The function label is written as (value = "new") => value. Which pair of call results is correct?

label(undefined) gives undefined; label(null) gives new
label(undefined) gives new; label(null) gives new
label(undefined) gives new; label(null) gives nullالإجابة الصحيحة
Both calls throw because defaults require no argument syntax

الشرح

A default initializer is selected for a missing argument or one explicitly equal to undefined, so label(undefined) gives new. Passing null supplies an actual argument, so label(null) preserves null rather than treating it as absent.

الشرح

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