CamelCaseとは 意味・読み方・使い方

別の表記

• camelcase, camelCase, CamelCase

語源

From camel +‎ case (“nature of a piece of alphabetic type”), probably modelled after lowercase and uppercase, from a fancied resemblance of the capital letters to the humps of a two-humped camel.

発音

• (Received Pronunciation) IPA: /ˈkæml̩ keɪs/
• (General American) IPA: /ˈkæm(ə)l ˌkeɪs/
• ハイフネーション: ca‧mel case

名詞

camel case (uncountable)

1. (typography, often programming) Especially in computer programming, and in the names of brands and organizations: a style of typography in which several words are concatenated together without any spaces between them, with the first letter of each word (sometimes excluding the first word) capitalized. [from 1990s]

   Hyponyms: upper camel case, UpperCamelCase, Pascal case, studly caps; bicapitalization, BiCapitalization; lower camel case, lowerCamelCase

   Coordinate terms: all caps, alternating caps, downstyle, initial caps, headline style, sentence case, title case, lowercase, upstyle

   Synonyms: camelback, HumpyCase (obsolete)

   Near-synonyms: intercapping, intercaps

   • 2001 September, Jennifer Niederst, “Introduction to SMIL”, in Lorrie LeJeune, Richard Korman, editors, Web Design in a Nutshell: A Desktop Quick Reference, 2nd edition, Sebastopol, Calif.: O’Reilly Media, →ISBN, page 457:

     In the SMIL 1.0 specification, test criteria were hyphenated (e.g., system-bitrate and system-screen-size). This was deprecated by the SMIL 2.0 specification in favor of camel case attributes to be consistent with other developing standards.

   • 2003, Rob Birdwell [et al.], “Introduction to Objects”, in Beginning ASP.NET 1.0 with C#, Wrox Programmer to Programmer, Wiley Publishing, →ISBN, page 298:

     It's common practice to name private members in camelCase, that is with an initial lower case letter and a capital for the start of each word.

   • 2003, Berthold Daum, Udo Merten, “Groundwork”, in System Architecture with XML, San Francisco, Calif.: Morgan Kaufmann Publishers, →ISBN, page 81:

     Write element and attribute names in a style called "CamelCase." Elements reflecting an entity should be written in UpperCamelCase; elements and attributes reflecting a property should be written in lowerCamelCase.

   • 2004 January, Michael Brundage, “Practical Examples”, in XQuery: The XML Query Language, Boston, Mass.: Addison-Wesley, →ISBN, part III (Application), pages 195–196:

     Type and attribute names, and occasionally variable names, are traditionally written using camel case (with the first word lowercased and subsequent words title-cased, like dateTime), although there are exceptions to this rule (such as anyURI and QName), and some people prefer hyphenated lowercase words (like local-name).

   • 2009, John Paul Mueller, “Coding the Application”, in C# Design and Development (Expert One-on-One), Indianapolis, Ind.: Wrox Programmer to Programmer, Wiley Publishing, →ISBN, page 243:

     RadioShack is an example of a company name that uses camel case. In some cases, technology uses camel case, such as VistaVision, which is a widescreen format for movies. It's little wonder that camel case appears in application code—everyone already knows how to use it. […] Microsoft and other industry leaders have modified the standard use of camel case. When you talk about camel casing for .NET, what you really mean is that the first letter of each word, except the first word, is capitalized. For example, if you want to create a variable that contains the background color for an object, you might call it backColor.

   • 2023, Jenny Gibson Bond, “Variables and Components”, in Mark Taub, editor, Introduction to Game Design, Prototyping, and Development, 3rd edition, Boston, Mass.: Addison-Wesley, →ISBN, part II (Programming C# in Unity):

     CamelCase is a common way of writing variable names in programming. It allows the programmer or someone reading their code to easily parse long variable names. […] The key feature of camelCase is that it allows multiple words to be combined into one with a medial capital letter at the beginning of each original word. It is named camelCase because it looks a bit like the humps on a camel's back.

使用する際の注意点

• Camel case is often used as one of multiple conventions for the names of variables in programming languages: compare MyVariableName (Pascal case or upper camel case), myVariableName (lower camel case) myvariablename (lower case), my_variable_name (snake case), and my-variable-name (kebab case or dash case).

派生語

関連する語

参考

参照

Further reading

• camel case on Wikipedia.Wikipedia