String (computer science): Difference between revisions

Revision as of 21:09, 6 January 2025

Revision as of 11:39, 8 February 2025

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==History==

Use of the word "string" to mean any items arranged in a line, series or succession dates back centuries.<ref>{{cite encyclopedia |encyclopedia=The Oxford English Dictionary |volume=X |publisher=Oxford at the Clarendon Press |year=1933 |title=string }}</ref><ref>{{cite web |title=string (n.) |url=https://www.etymonline.com/search?q=string |website=Online Etymology Dictionary }}</ref> In 19th-Century century typesetting, [[Compositor (typesetting)|compositors]] used the term "string" to denote a length of type printed on paper; the string would be measured to determine the compositor's pay.<ref>{{cite encyclopedia |encyclopedia=The Century Dictionary |author-link1=William Dwight Whitney |author-link2=Benjamin Eli Smith |first1=William Dwight |last1=Whitney |first2=Benjamin E. |last2=Smith |publisher=The Century Company |___location=New York |page=5994 |title=string }}</ref><ref name=Burchfield1986 /><ref>{{cite news |newspaper=[[Milwaukee Journal Sentinel|Milwaukee Sentinel]] |date=January 11, 1898 |title=Old Union's Demise |page=3 }}</ref>

Use of the word "string" to mean "a sequence of symbols or linguistic elements in a definite order" emerged from mathematics, [[symbolic logic]], and [[linguistic theory]] to speak about the [[formal system|formal]] behavior of symbolic systems, setting aside the symbols' meaning.<ref name=Burchfield1986>{{cite encyclopedia |title=string |encyclopedia=A Supplement to the Oxford English Dictionary |year=1986 |last=Burchfield |first=R.W. |publisher=Oxford at the Clarendon Press |author-link=Robert Burchfield }}</ref>

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=== String length ===

Although formal strings can have an arbitrary finite length, the length of strings in real languages is often constrained to an artificial maximum. In general, there are two types of string datatypes: ''fixed-length strings'', which have a fixed maximum length to be determined at [[compile time]] and which use the same amount of memory whether this maximum is needed or not, and ''variable-length strings'', whose length is not arbitrarily fixed and which can use varying amounts of memory depending on the actual requirements at run time (see [[Memory management]]). Most strings in modern [[programming languages]] are variable-length strings. Of course, even variable-length strings are limited in length – by the sizeamount of available [[computer memory]]. The string length can be stored as a separate integer (which may put another artificial limit on the length) or implicitly through a termination character, usuallyknown as a character[[null-terminated valuestring]] withor alla bits"C zerostring", suchnamed asafter in Cthe programming language. See also "[[#Null-terminatedC (programming language)|Null-terminatedC]]" below.

=== Character encoding ===