Antipatterns from the Textbook

SENG 365 — Software Engineering

Neil Ernst

University of Victoria

2026-10-30

Antipatterns

Antipatterns: Duplication, God Class, Intimacy

Antipattern	Symptom	Pages
Duplicated Code	The same logic is written in several places, so each change must be repeated.	11, 109, 158, 159, 183, 190, 235, 248, 251, 252 (index: 252). p. 178 spells it “Code Duplication”.
God Class	One class collects data and behaviour until it knows and does everything.	125 (ch. opener), 127, 139, 222 (index: 127)
Inappropriate Intimacy	Classes work through each other’s internals, for example only via getters and setters.	13 (ch. opener), 25

Antipatterns: Methods and Chains

Antipattern	Symptom	Pages
Long Method	A method is too long or complex to read at a glance.	11, 67 (ch. opener), 81, 95 (index: 81)
Message Chain	Client code navigates through a chain of objects, so it depends on the structure behind them.	125 (ch. opener), 154
Pairwise Dependencies	Every component updates every other directly to keep shared state in step.	193 (ch. opener), 195, 238 (index: 194)

Antipatterns: Primitives and Generality

Antipattern	Symptom	Pages
Primitive Obsession	Ints and strings stand in for domain concepts that deserve their own abstraction.	13 (ch. opener), 16, 17, 21, 22, 40 (index: 15)
Speculative Generality	Flexibility is built in for needs that may never arise.	67 (ch. opener), 73, 228, 253 (index: 73, 253)

Antipatterns: Branching and Fields

Antipattern	Symptom	Pages
Switch Statement	Code branches on a type or flag where separate objects could carry the behaviour.	43 (ch. opener), 51, 139, 144, 147, 184, 213 (index: 51)
Temporary Field	A field is used only under limited conditions and is not part of the object’s essential state.	67 (ch. opener), 73, 95 (index: 73)