camelCase

CamelCase is a style of writing compound words or phrases without spaces, in which internal word boundaries are indicated by capitalizing the first letter of each word after the initial one. The term camelCase is sometimes capitalized as CamelCase or PascalCase when the first letter is also capitalized. The two common variants are lower camel case (also called dromedaryCase) in which the first letter is lowercase, and upper camel case (also called PascalCase) in which the first letter is uppercase.

CamelCase is widely used in programming to form identifiers such as variable names, function names, and class names. In many languages, lowerCamelCase is used for variables and methods (for example thisIsMyVariable or doSomething), while PascalCase is used for class names (for example MyClass). Some languages have strong conventions around these styles, but others are more flexible. Other casing styles exist, such as snake_case and kebab-case, which use underscores or hyphens; camelCase avoids spaces and punctuation that would not be valid in identifiers.

The practice gained prominence with modern languages such as Java, JavaScript, and C# in the 1990s and 2000s, where camelCase became a widely adopted convention for naming identifiers. Style guides in these ecosystems often specify when to use lowerCamelCase versus PascalCase, and some languages enforce the convention through compiler checks or linters. Historical variants vary in capitalization rules and regional usage, but the general idea remains to improve readability while avoiding spaces.