Reserved Word

Reserved Word

Reserved words (occasionally called keywords) are one type of grammatical construct in programming languages. These words have special meaning within the language and are predefined in the language’s formal specifications. Typically, reserved words include labels for primitive data types in languages that support a type system, and identify programming constructs such as loops, blocks, conditionals, and branches.

The list of reserved words in a language are defined when a language is developed. Occasionally, depending on the flexibility of the language specification, vendors implementing a compiler may extend the specification by including non-standard features. Also, as a language matures, standards bodies governing a language may choose to extend the language to include additional features such as object-oriented capabilities in a traditionally procedural language. Sometimes the specification for a programming language will have reserved words that are intended for possible use in future versions. In Java, const and goto are reserved words — they have no meaning in Java but they also cannot be used as identifiers. By "reserving" the terms, they can be implemented in future versions of Java, if desired, without "breaking" older Java source code. Reserved words may not be redefined by the programmer, unlike predefined functions, methods, or subroutines, which can often be overridden in some capacity. The name of a predefined function, method, or subroutine is typically categorized as an identifier instead of a reserved word.

Read more about Reserved Word:  Reserved Word Vs. Keyword, Comparison By Language, Reserved Words and Language Independence

Other articles related to "words">reserved word":

Reserved Words and Language Independence
... Because of this, identifier/reserved word collisions can occur when code implemented in one language tries to execute code written in another language ... wishing to define a variable of type “this” would encounter a problem 'this' is a reserved word in C# ... which forces it to be considered an identifier rather than a reserved word by the compiler ...
Reserved Identifier - Reserved Words and Language Independence
... Because of this, identifier/reserved word collisions can occur when code implemented in one language tries to execute code written in another language ... of type “this” would encounter a problem 'this' is a reserved word in C# ... it to be considered an identifier rather than a reserved word by the compiler ...

Famous quotes containing the words word and/or reserved:

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    Henry Fielding (1707–1754)

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    Alexander Pope (1688–1744)