menu_book Course Curriculum (Ruby) expand_more
Prepend
Learn prepend in Ruby through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.
prepend is an atomic Ruby topic inside Inheritance and Modules. The example uses the named construct directly so you can see its syntax, data flow, and observable behavior.
Read the code by locating the exact feature named prepend, then trace the value before and after that feature runs. This lesson is intentionally isolated from neighboring topics: changing identifiers alone would not reproduce the same behavior because the construct itself is different.
Topic-specific example
module Trace;def call;"trace>"+super;end;end;class S;def call;"service";end;prepend Trace;end;puts S.new.call
For prepend, test the boundary that makes the feature meaningful: invalid input, an empty value, a missing branch, lifecycle/cleanup, or a type/runtime constraint. Do not infer correctness only from the happy path.