Code Smells

Code Smells / Object-Orientation Abusers / Switch Statement

Switch Statement

A Switch Statement code smell occurs whenever a switch statement is used. If instead of an actual switch statement, an if ... else if statement is used, this is still a Switch Statement code smell.

Switch statements can be considered good design in a procedural programming paradigm, but in Object-oriented programming, switch statements are a sign that the inheritance hierarchy is bad, or under-used.

# Smelly code
class Vehicle:
    def __init__(name):
        self.name = name

if vehicle.name == "Car":
    print(4)
elif vehicle.name == "Motorbike":
    print(2)
elif vehicle.name == "Tricycle":
    print(3)
else:
    print("Unknown")

# Improved
class Vehicle:
    def __init__():
        self.tyres = None
    
    def get_tyres():
        return self.tyres

class Car:
    def __init__():
        super()
        self.tyres = 4

class Motorbike:
    def __init__():
        super()
        self.tyres = 2

class Tricycle:
    def __init__():
        super()
        self.tyres = 3

print(vehicle.get_tyres())

Books about code smells

Learn to write better smelling code.

Refactoring: Improving the Design of Existing Code

Code smells: A Predictor of Remarkable Quality Improvement

Clean Code: A Handbook of Agile Software Craftsmanship

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