In software development, variable naming conventions are crucial for code readability, maintainability, and consistency. Different approaches exist depending on the language, development practices, or team conventions. Here are the most common types of variable naming conventions:

1. Camel Case (camelCase)

   Common in: JavaScript, Java, Swift, TypeScript
   Format: First word in lowercase, subsequent words are capitalized.
   Example: orderStatus, customerName, totalPrice

2. Pascal Case (PascalCase)

   Common in: C#, .NET, TypeScript (for classes, enums)
   Format: Each word starts with an uppercase letter, including the first word.
   Example: OrderStatus, CustomerName, TotalPrice

3. Snake Case (snake_case)

   Common in: Python, Ruby, PHP, C
   Format: Words are lowercase and separated by underscores.
   Example: order_status, customer_name, total_price

4. Kebab Case (kebab-case)

   Common in: URLs, some configurations, CSS class names
   Format: Words are lowercase and separated by hyphens.
   Example: order-status, customer-name, total-price

5. Upper Snake Case (UPPER_SNAKE_CASE)

   Common in: Constants, environment variables (in many languages like Python, C, Go)
   Format: All uppercase letters with words separated by underscores.
   Example: ORDER_STATUS, CUSTOMER_NAME, TOTAL_PRICE

6. Hungarian Notation

   Common in: Older C++, legacy systems (less common now)
   Format: Variable names are prefixed with letters representing the variable type.
   Example: strCustomerName (string), iTotalPrice (integer)

7. Screaming Snake Case

   Common in: Environment variables, constants
   Similar to snake case but all characters are uppercase, often used for constants or global variables.
   Example: MAX_USER_COUNT, ENVIRONMENT_MODE

8. Abbreviation-Based Naming

   Common in: Small variable names or indexing operations
   Format: Abbreviated form of the variable’s purpose.
   Example: idx for index, cnt for count, msg for message

9. Domain-Specific Naming

   Based on: Domain-driven design or business logic
   Example: invoiceData, productCategory, shippingStatus

Best Practices for Variable Naming:

Descriptive & Meaningful: Variables should represent their purpose. For example, instead of using x, use productPrice or orderCount.
Avoid Single Letters: Except for loop counters (e.g., i, j), avoid single-letter variable names.
Use Consistent Conventions: Choose one naming convention (like camelCase or snake_case) and use it consistently across the codebase.
Avoid Abbreviations: Unless they're well-known, avoid abbreviations that can confuse others reading the code.