Case Conversion in Code: camelCase, snake_case, PascalCase Explained

Every programming language has its own naming conventions. Using the wrong case for variables, classes, or constants isn't just a style issue — in some languages and frameworks, it can cause runtime errors or prevent your code from working at all.

camelCase: JavaScript and Java Standard

First word lowercase, subsequent words start with uppercase. No separators. getUserProfile, isLoggedIn, fetchApiData

• JavaScript: variables and functions use camelCase
• Java: methods and variables use camelCase
• Swift: methods and variables use camelCase

PascalCase: Classes and Types

Every word starts with uppercase. No separators. UserProfile, HttpClient, DataRepository

• Classes in JavaScript, Python, Java, C#, TypeScript
• React components (both naming convention and requirement)
• TypeScript interfaces and types

snake_case: Python and Database Standard

All lowercase, words separated by underscores. get_user_profile, is_logged_in, user_id

• Python: all variables, functions, and module names
• SQL: column and table names
• Ruby: methods and variables

kebab-case: CSS and URLs

All lowercase, words separated by hyphens. my-css-class, blog-post-title, user-profile-section

• CSS class names and ID attributes
• URL slugs (blog/how-to-merge-pdf-files-free)
• HTML data attributes (data-user-id)

SCREAMING_SNAKE_CASE: Constants

All uppercase, underscores as separators. MAX_FILE_SIZE, API_BASE_URL, DEFAULT_TIMEOUT_MS

Used for constants in Python, Java, C, and most other languages.