Text Casing Conventions in Programming: camelCase, snake_case & More

Consistent variable and identifier naming is essential for software maintainability, team collaboration, and automated code linting. Different programming languages, database systems, and serialization formats enforce strict conventions. Understanding when to apply camelCase, PascalCase, snake_case, and kebab-case avoids costly syntax errors and code review friction.

The Four Major Casing Conventions Explained

1. camelCase

In camelCase, words are joined without spaces. The first word is entirely lowercase, and each subsequent word begins with an uppercase letter.

let userAccountBalance = 450.25;
function calculateMonthlyRevenue() { ... }

Primary Use Cases: JavaScript/TypeScript variables, methods, and functions; Java method identifiers; JSON property keys.

2. PascalCase (UpperCamelCase)

PascalCase is identical to camelCase except that the very first character is capitalized as well.

class PaymentProcessor extends BaseService { ... }
type UserProfileResponse = { id: string; name: string };
const UserAvatarComponent = () => { ... };

Primary Use Cases: Class names in Python, Java, C#, C++; React and Vue component names; TypeScript interfaces and type aliases.

3. snake_case

In snake_case, all words are lowercase and separated by an underscore (_).

user_account_balance = 450.25
def calculate_monthly_revenue(): ...

Primary Use Cases: Python functions and variable names (PEP 8 standard); SQL column and table names; Rust variable identifiers; Linux system configuration keys.

4. kebab-case (lisp-case / dash-case)

In kebab-case, all letters are lowercase and words are delimited by hyphens (-).

.user-profile-header {
    background-color: #f7fafc;
}
https://toolkitbank.com/text-tools/case-converter

Primary Use Cases: CSS class and ID selectors; HTML attribute names; REST API URL endpoints and slugs; package names in npm.

Quick Reference Cheat Sheet