About camelCase to snake_case Conversion
Converting between camelCase and snake_case is essential when working across different programming languages. JavaScript and Java use camelCase (myVariableName), while Python and Ruby prefer snake_case (my_variable_name).
Common Use Cases
- API Translation: Convert JSON camelCase keys to Python snake_case
- Code Migration: Port JavaScript code to Python
- Database Columns: Most SQL databases use snake_case naming
- Style Compliance: Follow PEP 8 (Python) or Ruby style guides
Conversion Rules
This tool applies the following transformations:
- Detects uppercase letters following lowercase letters
- Inserts underscore before each uppercase letter
- Converts all letters to lowercase
- Handles spaces and hyphens by replacing with underscores
Examples:
myVariableName→my_variable_namegetUserData→get_user_datacalculateTotalPrice→calculate_total_priceHTTPSConnection→https_connection
Language-Specific Naming Conventions
| Language | Convention | Example |
|---|---|---|
| JavaScript | camelCase | getUserData() |
| Python | snake_case | get_user_data() |
| Ruby | snake_case | get_user_data |
| SQL | snake_case | user_data |
When to Use snake_case
- Python: PEP 8 mandates snake_case for variables and functions
- Ruby: Community standard for methods and variables
- Databases: SQL table and column names traditionally use snake_case
- Configuration Files: YAML, TOML often prefer snake_case keys
- REST APIs: Some API designs use snake_case in URLs
Frequently Asked Questions
What's the difference between camelCase and snake_case?
camelCase joins words by capitalizing each word except the first (myVariableName), while snake_case uses underscores to separate all-lowercase words (my_variable_name).
Which is better: camelCase or snake_case?
Neither is inherently better. Use camelCase for JavaScript/Java/C# code, and snake_case for Python/Ruby/SQL. Following your language's conventions makes code more readable to other developers.
Does this work with PascalCase?
Yes! PascalCase (MyClassName) converts to snake_case (my_class_name) the same way camelCase does.
Can I convert multiple variables at once?
Yes, paste multiple camelCase names (one per line) and they'll all be converted to snake_case.