Chapter 2 (Meaningful names)

Create correct names

• The length of a name MUST match it’s scope size
• The name of a class MUST NOT be a verb
• Methods MUST have verb names
• Don’t be afraid of changes regarding variable names (as long as it’s for the better)

Reveal the intention

• Why does it exists?
• What does it do?
• How it’s used?
• If a name requires a comment, then it’s not revealing it’s intention

Avoid disinformation

• DO NOT user names which are away from it’s intended usage meaning
• Avoid names with minimal variation:

  MethodUsedForHandlingOfStrings
  MethodUsedForEfficientStorageOfStrings
  

Meaningful distinction

• DO NOT create code targeting only the compiler/interpreter
• Names with numerical series (a1, a2) do not hold an intention, they misinform
• Additional words are redundant (e.g: a, an, the, variable, info, data, table, NameString)

  // different names but same meaning
  class Product
  class ProductInfo
  class ProductData
  

Pronounceable

• Use pronounceable names (humans can do words fine, if it can’t be pronounced it can’t be explained)

Searchable

• Single letter names and numerical constants are NOT easy to find

Avoid encoding

• Encoding types or scopes into a name it makes harder to decode
• It IS NOT reasonable for new employees to learn yet another language of the encoding on top of the code they will work on.

Avoid mental mappings

• Single letter variables are OK for loop counters
• Avoid the reader having to map the variable with a concept mentally (explicit is better)
• The difference between a smart programmer and a professional programmer is that the later knows that clarity is what matters

One word per concept

• Avoid synonyms for equivalent methods (get, fetch, retrieve)
• A coherent lexical is an advantage for programmers using your code

Avoid word confusions

• DO NOT use the same word if there’s semantic difference:

  A method that adds values to an existing object is different to a list of the same object, which has a method to add new elements. Using the same word creates confusion for which there is a semantic difference