Letter Case (Programming Conventions)

In programming, letter case conventions, such as Camel Case, Pascal Case, Snake Case, and Kebab Case, determine the capitalization patterns of identifiers. These conventions, originating from early computer science traditions, play a pivotal role in ensuring clarity and aligning with specific language design principles.


Letter case in programming refers to the convention governing the use of upper and lowercase letters in identifiers. An identifier in programming denotes names given to different elements such as variables, functions, classes, and more.


Different letter cases in programming languages have historical roots. As programming languages evolved, conventions emerged, influenced not only by the design philosophy of the language but also by the practices and preferences of its user community.

Primary Types

  • Camel Case: Begins with a lowercase letter, with each subsequent word capitalized. This naming resembles the humps of a camel. Example: variableName.
  • Pascal Case: Similar to camel case but starts with an uppercase letter. It’s named after the Pascal programming language, which favored this style for its clarity and readability. Example: ClassName.
  • Snake Case: Words are separated by underscores. This style is prevalent in languages like Python, where the community values code readability. The underscores visually separate words, making multi-word identifiers easier to read. Example: variable_name.
  • Kebab Case: Uses hyphens to separate words. It’s common in contexts like URLs or CSS class names where underscores or spaces may be problematic. Example: variable-name.

Reasons for Conventions

  • Readability: Different cases in code help distinguish between types of identifiers, making it easier for developers to understand the purpose and role of each element.
  • Syntax Requirements: Some programming languages are case-sensitive, meaning variableName and VariableName would be treated as two distinct identifiers. This distinction necessitates clear naming conventions to avoid errors.
  • Historical Precedents: The traditions of early programming languages have set certain conventions which newer languages have either adopted or adapted.


  • Language Design: The default naming convention of a language often mirrors its design philosophy. For example, Java, an object-oriented language, typically uses Pascal Case for class names and camelCase for method names.
  • Coding Standards: Different organizations or projects might adopt specific naming conventions that they find best align with their goals, irrespective of the general conventions of the language they are using.
  • Compiler and Interpreter Design: The design of a programming language’s compiler or interpreter can impact naming conventions, especially in languages where case-sensitivity can lead to different outcomes in code execution.

Practical Implications

  • Consistency: Many projects maintain a consistent naming convention across their codebase for uniformity.
  • Error Avoidance: Inconsistent or incorrect naming, especially in case-sensitive languages, can lead to errors that prevent the code from running as expected.
  • Documentation and Collaboration: In collaborative environments, a shared understanding of naming conventions ensures that team members can easily read and understand each other’s code.
  • Tooling and IDE Impact: Naming conventions can influence the functionality of development tools. For instance, an IDE’s auto-completion feature might rely on specific naming patterns to suggest relevant code snippets.

Historical Note

The history of naming conventions is intertwined with the evolution of programming languages. For instance, the Pascal programming language, developed in the 1970s, played a significant role in popularizing Pascal Case, setting a precedent for future languages and developers.