First programming lesson: Control structures. Senior developer lesson: avoid them.

Problems

• Too many decisions together

• Coupling

• Duplicated code

• Violation of Open/Closed Principle.

• A new condition should not change the main algorithm.

• Nulls

Solutions

1. Polymorphism

2. Create hierarchies/compose objects following Open closed principle.

3. Use State pattern to model transitions.

4. Use Strategy Pattern/Method Object to choose for branches.

Examples

• Discrete Values

• State transition

• Algorithm choice.

Sample Code

Wrong

Right

Detection

Since there are valid cases for If/else usages, we should not pull the plug and forbid these instructions. We can put a ratio of if statements/other statements as a warning instead.

Relations

More info

Credits

Photo by Adarsh Kummur on Unsplash

If debugging is the process of removing software bugs, then programming must be the process of putting them in.

Edsger Dijkstra

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This article is part of the CodeSmell Series.