When to use camelCase, PascalCase, UPPER_CASE, kebab-case, and snake_case.

Ultimately, it’s dependent on language.

JavaScript

  • camelCase
    • variableNames
    • objectMethods
  • PascalCase
    • ClassDeclarations
    • Enums
  • UPPER_CASE
    • GLOBAL_VARIABLES
    • ENUM_OPTION (also preferred to be singular nouns)
    • CONSTANTS (like Pi)
  • kebab-case
    • Not allowed in JavaScript, although CSS uses it extensively
  • snake_case
    • Not a thing in JavaScript, although file names on servers use it

Languages Using Each

  • camelCase
    • Java & JavaScript
  • PascalCase
    • Coding in C
  • UPPERCASE
  • lowercase
    • filenames on servers
  • kebab-case
    • CSS
  • snake_case
    • SQL

Source

Google JavaScript Style Guide