menu_book Course Curriculum (Smalltalk Complete Course) expand_more
ensure:
Learn ensure: in Smalltalk with a construct-specific explanation, a unique example, a practical boundary, and a mastery check.
ensure: is an atomic Smalltalk topic inside Blocks & Control. The example below uses the actual construct named by the lesson rather than a generic placeholder.
Focus on what ensure: changes: the input, binding, control path, object state, collection, runtime effect, or language contract. Then alter one value and verify that the behavior changes for a reason specific to this feature.
Topic-specific example
[ Transcript show: 'work' ] ensure: [ Transcript show: 'cleanup' ].
Exercise both the success path and the failure path; verify what is caught, propagated, or cleaned up rather than only checking printed output.