Refactoring: Improving the Design of Existing Code

Chapter 9. Simplifying Conditional Expressions

Conditional logic has a way of getting tricky, so here are a number of refactorings you can use to simplify it. The core refactoring here is Decompose Conditional (238), which entails breaking a conditional into pieces. It is important because it separates the switching logic from the details of what happens.

The other refactorings in this chapter involve other important cases. Use Consolidate Conditional Expression (240) when you have several tests and all have the same effect. Use Consolidate Duplicate Conditional Fragments (243) to remove any duplication within the conditional code.

If you are working with code developed in a one exit point mentality, you often find control flags that allow the ...