Smell Switch Statements

The same switch statement scattered about a program in different places. If you add a new clause to the switch, you have to find all these switch statements and change them. The object-oriented notion of polymorphism gives you an elegant way to deal with this problem.

• Switch statements that switch on type codes
• Same switch statement duplicated in multiple places
• Conditionals that determine behavior based on object type

Martin Fowler — Refactoring: Improving the Design of Existing Code, 1st Edition (1999)