CS 2340: Design Principles & Patterns

GRASP

assign responsibilities of classes & objects

Creator

GRASP

class should create objects it closely uses

Information expert

GRASP

assign responsibility to class that has needed data

Low coupling

GRASP

minimize dependencies between classes

High cohesion

GRASP

keep classes focused, not overloaded

Controller

GRASP

separate UI from model

Polymorphism

GRASP

implementing classes

Pure fabrication

GRASP

make helper classes when no natural class works

Indirection

GRASP

add middle layer between classes for less dependency

Protected Variations

GRASP

protect system from what can change

SOLID

design & relationship of classes

Single responsibility

SOLID

one class = one job

Open/closed

SOLID

open for extension, closed for modification

Liskov substitution

SOLID

child objects can replace parent objects

Interface segregation

SOLID

client shouldn’t depend on methods it doesn’t use

Dependency inversion

SOLID

high-level classes shouldn’t depend on low-level classes

Singleton pattern (creational)

ensures only one instance of a class with global access

Factory method pattern (creational)

standard mechanism for object creation

Strategy pattern (behavioral)

encapsulate interchangeable behaviors, swap algorithms without changing the main code

Visitor pattern (behavioral)

add new operations to existing objects without altering object’s code