Convert any phrase into PascalCase — every word capitalised, no separators. Standard for class names, types, and React components.
user profile background color → UserProfileBackgroundColor
PascalCase (sometimes called UpperCamelCase or StudlyCaps) is a naming convention where every word starts with an uppercase letter and there are no separators between words. It's the standard for class names, type names, and constructor functions in nearly every modern language.
The convention is named after the Pascal programming language (1970s), which used it for type names. The closely-related camelCase differs only in the first letter — PascalCase capitalises the first word; camelCase lowercases it.
UserProfile, HttpClient, OrderRepository. Java, C#, TypeScript, Swift, Kotlin, and Python (PEP 8) all use PascalCase for class names regardless of what they use for variables.
React requires component names to be PascalCase — <UserCard /> not <userCard />. JSX uses the casing to decide whether a tag is a custom component (capitalised) or an HTML element (lowercase).
Interface names (UserSettings, ApiResponse) and type aliases are PascalCase. Some teams prefix interfaces with I (IUserSettings); the modern TypeScript convention is to skip the prefix.
Most languages use PascalCase for enum members: OrderStatus.Pending, HttpStatus.NotFound. (Some older C++ code uses CONSTANT_CASE for enums; modern usage favours PascalCase.)
If a file defines a class, the file name often matches the class name in PascalCase: UserProfile.tsx, OrderService.cs.
Both are correct in different contexts. camelCase for variables, function names, and object properties. PascalCase for classes, types, and (in React) components. Most languages use both — they're complementary, not interchangeable.
The Pascal language (designed by Niklaus Wirth, 1970) used UpperCamelCase for type names — popularising the convention enough that it took the language's name. Pascal itself is no longer mainstream, but the naming convention outlived it.
Two schools of thought: full caps (HTTPClient, XMLParser) or treated-as-words (HttpClient, XmlParser). Microsoft and most modern style guides recommend the latter (treat acronyms ≥ 3 letters as words). It scans more uniformly inside long identifiers.
StudlyCaps is the same convention as PascalCase but the term is older (1980s) and slightly more informal. The two names refer to the identical pattern.