Dispensables

A dispensable is something pointless and unneeded whose absence would make the code cleaner, more efficient and easier to understand.

Comments

A method is filled with explanatory comments. If you feel that a code fragment can’t be understood without comments, try to change the code structure in a way that makes comments unnecessary. The best comment is a good name for a method or class.

However, comments can be useful when explaining why something is being implemented in a particular way or complex algorithms.

Treatment

• Extract Variable

• Extract Method

• Rename Method

• Introduce Assertion

Duplicate Code

Two code fragments look almost identical.

Treatment

• Extract Variable

• Extract Method

Lazy Class

Understanding and maintaining classes always costs time and money. So if a class doesn’t do enough to earn your attention, it should be deleted.

Treatment

• Inline Class

• Collapse Hierarchy

Data Class

A data class refers to a class that contains only fields and crude methods for accessing them (getters and setters). These are simply containers for data used by other classes.

Dead Code

A variable, parameter, field, method or class is no longer used (usually because it’s obsolete).

Treatment

• Delete unused code and unneeded files.

• Inline Class or Collapse Hierarchy can be applied if a subclass or superclass is used.

• To remove unneeded parameters, use Remove Parameter.

Speculative Generality

There’s an unused class, method, field or parameter.