Meaningful Names

Robert C. Martin

Book Notes

Best Practices

Avoid Disinformation

Extracted from the book Clean Code pages 19 - 20

Avoid using similar names where it’s difficult to spot the difference because it can lead to a programmer mistakenly using one name instead of the other.

Beware of using names that vary in small ways. How long does it take to spot the difference between a XYZControllerForEfficientHandlingOfStrings in one module and, somewhere a little more distant, XYZControllerForEfficientStorageOfStrings? The words have frightfully similar shapes.

Interfaces and Implementations

Extracted from the book Clean Code page 24

It’s better to encode the implementation by adding the suffix -Imp rather than encoding the interface.

These are sometimes a special case for encodings. For example, say you are building an ABSTRACT FACTORY for the creation of shapes. This factory will be an interface and will be implemented by a concrete class. What should you name them? IShapeFactory and ShapeFactory? I prefer to leave interfaces unadorned. The preceding I, so common in today’s legacy wads, is a distinction at best an too much information at worst. I don’t want my users knowing I’m handing them an interface. I just want them to know that it’s a ShapeFactory. So if I must encode either the interface or the implementation, I choose the implementation. Calling it ShapeFactoryImp, or even the hideous CShapeFactory, is preferable to encoding the interface.

Class Names

Extracted from the book Clean Code page 25

Classes and objects should have noun or noun phrase names like Customer, WikiPage, Account, and AddressParser. Avoid words like Manager, Processor, Data, or Info in the name of a class. A class name should not be a verb.

Method Names

Extracted from the book Clean Code page 25

Methods should have verb or verb phrase names like postPayment, deletePage, or save. Accessors, mutators, and predicates should be named with their value and prefixed with get, set, and is, according to the javabean standard.

When constructors are overloaded, use static factory methods with names that describe their arguments. For example,

Complex fulcrumPoint = Complex.FromRealNumber(23.0);

is generally better than

Complex fulcrumPoint = new Complex(23.0);

Consider enforcing their use by making the corresponding constructor private.

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