Void, Scalar, and List Context

Amount context

Amount context governs how many items we expect an operation to produce. Think of subject-verb number agreement in English. Even without knowing the formal description of this principle, you probably understand the error in the sentence, “Perl are a fun language.” (In terms of amount context, we could say that the verb “are” expects a plural noun or noun phrase.) In Perl, the number of items we request influences how many we receive.

Suppose the functionPerl uses the sub built-in to declare a function. called find_chores() sorts our household to-do list in order of priority. The number of chores we expect to read from our list influences what ...