In Chapter 2, we'll take a brief look at the refactoring cycle. Chapter 3 is about measurable smells ”those indicated by simple length metrics. Chapter 4 looks at how names contribute to the simplicity and comprehensibility of code. Chapter 5 considers the problem of unnecessary code.
The topic of Chapter 6 ”duplication ”is, in many ways, the core smell we need to be sensitive to. Many of the other smells can be regarded as special cases of duplication.
Section 1 closes with Chapter 7, a look at conditional logic: how the expressions used by conditional and loop statements can be made more clear.