Keyword (computer programming): Difference between revisions

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In [[computer programming]], a '''keyword''' is a [[word]] or [[identifier]] that has a particular meaning to the [[programming language]]. The meaning of keywords — and, indeed, the meaning of the notion of ''keyword'' — differs widely from language to language.

In many languages, such as [[C (programming language)|C]] and similar environments like [[C++]], a ''keyword'' is a [[reserved word]] which identifies a syntacticsyntact ic form. Words used in [[control flow]] constructs, such as <tt>if</tt>, <code>then</code>, and <code>else</code> are keywords. In these languages, keywords cannot also be used as the names of variables or functions.

In some languages, such as [[ALGOL]] and [[ALGOL 68|Algol 68]], keywords cannot be written verbatim, but must be [[Stropping (syntax)|stropped]]. This means that keywords must be marked somehow. E.g. by quoting them or by prefixing them by a special character.