Naming conventions should be clear and straightforward, regardless of class, variable, or method.
If there are no rules for naming within the team, there is a high possibility of a dispute over naming, and other team members may have different opinions, making it difficult to find an agreement.

Recently, there has been a debate in our team about abbreviation conventions.
In order to organize different thoughts, I organized naming conventions of companies such as Google, ms, oracle.
Ultimately, our team defined naming rules based on the compiled abbreviation conventions.

Package

  • Only lowercase letters and numbers are allowed in packages. (Oracle / Google)
    ✔️ com.example.deepspace
    ⚠️ com.example.deepSpace
    ⚠️ com.example.deep_space

Class

  • Class names should be nouns or noun phrases. (W3 / Oracle / Google)
    ✔️ SpaceShip
    ⚠️ launchSpaceship
  • The first letter of the class name should be capitalized. UpperCamelCase (W3 / Oracle / Google)
    ✔️ SpaceShip
    ⚠️ spaceship
    ⚠️ spaceShip

Variable

  • Variables should be in lowerCamelCase1. (W3 / Google / Oracle)
    ✔️ speed
    ⚠️ Speed
    ⚠️ SPEED
  • Variables should be nouns or noun phrases. (W3 / Google)
    ✔️ fuelLevel
    ⚠️ calculateFuel
  • Single-letter variables are not allowed except for temporary variables. (Oracle)
    ✔️ point
    ⚠️ p

Method

  • Methods should be verbs or verb phrases. (Oracle / Google)
    ✔️ calculateDistance
    ⚠️ distance
  • Methods should be in lowerCamelCase1. (Oracle / Google)
    ✔️ calculateDistance
    ⚠️ CalculateDistance
    ⚠️ calculate_distance

Constant

  • Constants should be all uppercase with words separated by _. (Oracle / Google)
    ✔️ MAX_SPEED
    ⚠️ MaxSpeed
    ⚠️ max_speed

Test

  • Test class names should end with the postfix “Test”. (Google)
    ✔️ CalculatorTest
    ⚠️ TestCalculator

Common Rules

  • The first letter of each word should be capitalized when multiple words are used internally. (Oracle / Google)
    ✔️ DeepSpaceMissionControlCenter
    ⚠️ deepspacemissioncontrolcenter
    ⚠️ deep_space_mission_control_center

  • Meaningless prefixes and postfixes should not be used. (Google)
    ✔️ name
    ⚠️ name_
    ⚠️ mName

Abbreviation Conventions

  • Full words should be used instead of abbreviations unless the abbreviation is more common and easily understood. (W3 / MS)
  • Even when using abbreviations, CamelCase2 should be applied. (MS)
    • For example, when creating a variable named UUIDIP, uuidIp is correct, and this applies even when using a single abbreviation like Id.
    • The reason for applying camelCase even to abbreviations is primarily because:
      1. It greatly enhances readability.
      2. Abbreviations are not confused. (For example, with abbreviations such as AB, CDE, ABC, DE, when there is ABCDE, it is unclear which abbreviation it is.)

    ✔️ JSON
    ⚠️ ID -> ️✔️ Id
    ⚠️ Win -> ️✔️ Window
    ⚠️ UUIDIPJSON -> ️✔️ UuidIpJson
    ⚠️ ABCDE -> ️✔️ AbcDe
    ⚠️ ABCDE -> ️✔️ AbCde

Reference

  1. Unlike CamelCase, lowerCamelCase starts with a lowercase letter. The first letter of each subsequent word is capitalized. ↩ ↩2

  2. CamelCase is a naming convention that mimics the humps of a camel, capitalizing the first letter of each word in a multi-word phrase. ↩