Percent sign

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Punctuation

The percent sign (%) is the symbol used to indicate a percentage (that the preceding number is divided by one hundred). It is represented in Unicode by U+0025.

Related signs include the permille sign ‰ (Unicode: U+2030) and the per ten thousand sign ‱ (Unicode: U+2031; also known as a basis point), which indicate that a number is divided by one thousand or ten thousand respectively. Higher proportions use parts-per notation.

The common prescription, in style guides, is to put these symbols after the number without any space in between.

[edit] Evolution

The symbol evolved from a symbol similar except for a horizontal line instead of diagonal (c. 1650), which in turn evolved from an abbreviation of "P cento" (c. 1425, from the Italian per cento "for a hundred")<ref>Weaver, Douglas. The History of Mathematical Symbols. Retrieved on 2006-07-18.</ref>.

"%" in the 15th century, an abbreviation of per cento

"%" in the 17th century, with only the o from cento remaining

"%" as soon as the 18th century; note the diagonal line

A different reference<ref>U+0025 PERCENT SIGN.</ref> tells a similar story. The phrase 'per cento' had several different abbreviations (e.g. 'per 100', 'p 100', 'p cento', etc.). At some point a scribe of some sort used the abbreviation 'pc' with a tiny loop (used in Italian numeration for primo, secundo, etc.). The 'pc' with a loop eventually evolved a horizontal fraction sign and lost the 'per'. In modern times, we use a solidus instead of the horizontal fraction bar.

Another story<ref>304 A Brief History of Percent.</ref> claims the symbol and name were developed in the Dark Ages by clever merchants. Apparently, priests thought numbers were evil, making the life of a merchant much harder. God revealed the percent sign to the merchants who claimed it expelled the evil from any number preceding it in speech and writing. The term was used in place of 'cent', so an item costing 120% would have cost 120 cents.

[edit] Usage in computers

In Unicode, there is also an "ARABIC PERCENT SIGN" ("٪"U+066A), which has the circles replaced by square dots set on edge.

In computing, the percent character is also used for the modulo operation in programming languages that derive their syntax from the C programming language, which in turn acquired this usage from the earlier B programming language.<ref>Thompson, Ken (1996). Users' Reference to B.</ref> The ASCII code for the percent character is 37, or 0x25 in hexadecimal. In the textual representation of URIs, a % immediately followed by a 2-digit hexadecimal number denotes a octet specifying (part of) a character that might otherwise not be allowed in URIs (see percent-encoding). Names for the percent sign include percent sign (in ITU-T), mod, grapes (in hacker jargon), and the humorous double-oh-seven (in INTERCAL).

The percent sign can also be used in many programming languages to represent all values. For example, the SQL query SELECT name FROM dbname WHERE id = '%' will fetch all records - finding rows with any value in the id column.

In Basic, a trailing % after a variable name marks it as an integer.

In the command processors COMMAND.COM (DOS) and CMD.EXE (OS/2 and Windows), %1, %2,... stand for the first, second,... parameters of a batch file. %VAR1% represents the value of an environment variable named VAR1. Thus:

set PATH=c:\;%PATH%

sets a new value for PATH, the old value preceded by "c:\".

[edit] Usage in linguistics

In linguistics, the percent sign is prepended to an example string to show that it is judged well-formed by some speakers and ill-formed by others. This may be due to differences in dialect or even individual idiolects. This is similar to the asterisk to mark ill-formed strings, the question mark to mark strings where well-formedness is unclear, and the number sign to mark strings that are syntactically well-formed but semantically nonsensical.

[edit] See also

• Punctuation
• Special characters

[edit] References

<references/>da:Procenttegn ko:%