The symbol , known in

Unicode Unicode or ''The Unicode Standard'' or TUS is a character encoding standard maintained by the Unicode Consortium designed to support the use of text in all of the world's writing systems that can be digitized. Version 16.0 defines 154,998 Char ...

as hyphen-minus, is the form of

hyphen The hyphen is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is called hyphenation. The hyphen is sometimes confused with dashes (en dash , em dash and others), which are wider, or with t ...

most commonly used in digital

document A document is a writing, written, drawing, drawn, presented, or memorialized representation of thought, often the manifestation of nonfiction, non-fictional, as well as fictional, content. The word originates from the Latin ', which denotes ...

s. On most keyboards, it is the only character that resembles a

minus sign The plus sign () and the minus sign () are mathematical symbols used to denote positive and negative functions, respectively. In addition, the symbol represents the operation of addition, which results in a sum, while the symbol represent ...

or a

dash The dash is a punctuation mark consisting of a long horizontal line. It is similar in appearance to the hyphen but is longer and sometimes higher from the baseline. The most common versions are the endash , generally longer than the hyphen ...

, so it is also used for these. The name ''hyphen-minus'' derives from the original

ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...

standard, where it was called ''hyphen (minus)''. The character is referred to as a ''hyphen'', a ''minus sign'', or a ''dash'' according to the context where it is being used.

Description

In early

typewriter A typewriter is a Machine, mechanical or electromechanical machine for typing characters. Typically, a typewriter has an array of Button (control), keys, and each one causes a different single character to be produced on paper by striking an i ...

s and

character encodings Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using computers. The numerical values that make up a c ...

, a single key/code was almost always used for hyphen, minus, various dashes, and strikethrough, since they all have a similar appearance. The current

Unicode Standard Unicode or ''The Unicode Standard'' or TUS is a character encoding standard maintained by the Unicode Consortium designed to support the use of text in all of the world's writing systems that can be digitized. Version 16.0 defines 154,998 cha ...

specifies distinct characters for several different

es, an unambiguous

(sometimes called the ''Unicode minus'') at

code point A code point, codepoint or code position is a particular position in a Table (database), table, where the position has been assigned a meaning. The table may be one dimensional (a column), two dimensional (like cells in a spreadsheet), three dime ...

U+2212, an unambiguous

(sometimes called the ''Unicode hyphen'') at U+2010, the hyphen-minus at U+002D and a variety of other hyphen symbols for various uses. When a hyphen is called for, the hyphen-minus is a common choice as it is well known, easy to enter on

keyboard Keyboard may refer to: Text input * Keyboard, part of a typewriter * Computer keyboard ** Keyboard layout, the software control of computer keyboards and their mapping ** Keyboard technology, computer keyboard hardware and firmware Music * Mus ...

s, and still the only form recognized by many data formats and computer languages. Though the Unicode Standard states that the U+2010 hyphen is "preferred" over the hyphen-minus, the standard itself uses the hyphen-minus as its hyphen character. In most modern

computer font A computer font is implemented as a digital data file containing a set of graphically related glyphs. A computer font is designed and created using a font editor. A computer font specifically designed for the computer screen, and not for printi ...

s, the hyphen-minus is either identical or very similar to the Unicode hyphen. In mathematical texts that include the plus sign, the Unicode minus is preferred to the hyphen-minus, because its metrics match the plus sign in level and length.

Uses

Typing

This character is typed when a hyphen or a minus sign is wanted. Based on old typewriter conventions, it is common to use a pair to represent an

em dash The dash is a punctuation mark consisting of a long horizontal line. It is similar in appearance to the hyphen but is longer and sometimes higher from the baseline. The most common versions are the endash , generally longer than the hyphen ...

, and to put spaces around it to represent a spaced en dash ; this practice is deprecated in professional

typography Typography is the art and technique of Typesetting, arranging type to make written language legibility, legible, readability, readable and beauty, appealing when displayed. The arrangement of type involves selecting typefaces, Point (typogra ...

. Some

word processor A word processor (WP) is a device or computer program that provides for input, editing, formatting, and output of text, often with some additional features. Early word processors were stand-alone devices dedicated to the function, but current word ...

s automatically convert these to the correct dash. The character can also be typed multiple times to simulate a horizontal line (though in most cases, repeated entry of the

underscore An underscore or underline is a line drawn under a segment of text. In proofreading, underscoring is a convention that says "set this text in italic type", traditionally used on manuscript or typescript as an instruction to the printer. Its ...

will produce a solid line). Alternating the hyphen-minus with spaces produces a "dashed" line, often to indicate where paper is to be cut. On a typewriter, over-striking a section of text with this is used for

strikethrough Strikethrough, or strikeout, is a typographical presentation of words with a horizontal line through their center, resulting in , sometimes an X or a forward slash is typed over the top instead of using a horizontal line. Strike-through was u ...

Programming languages

Some

programming language A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...

s use the hyphen-minus for denoting subtraction and

additive inverse In mathematics, the additive inverse of an element , denoted , is the element that when added to , yields the additive identity, 0 (zero). In the most familiar cases, this is the number 0, but it can also refer to a more generalized zero el ...

, often called ''negation'' in this context. It is rarely used to indicate a range, due to ambiguity with subtraction. Generally, other characters, such as the Unicode are not recognized as an

operator Operator may refer to: Mathematics * A symbol indicating a mathematical operation * Logical operator or logical connective in mathematical logic * Operator (mathematics), mapping that acts on elements of a space to produce elements of another sp ...

. In some programming languages (for example

MySQL MySQL () is an Open-source software, open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, and "SQL", the acronym for Structured Query Language. A rel ...

) (two hyphen-minus) mark the beginning of a

comment Comment may refer to: Computing * Comment (computer programming), explanatory text or information embedded in the source code of a computer program * Comment programming, a software development technique based on the regular use of comment tags ...

. It can be used to start the

signature block A signature block (often abbreviated as signature, sig block, sig file, .sig, dot sig, siggy, or just sig) is a personalized block of text automatically appended at the bottom of an email message, Usenet article, or Internet forum, forum post. E ...

Usenet Usenet (), a portmanteau of User's Network, is a worldwide distributed discussion system available on computers. It was developed from the general-purpose UUCP, Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Elli ...

news system.

YAML YAML ( ) is a human-readable data serialization language. It is commonly used for configuration files and in applications where data is being stored or transmitted. YAML targets many of the same communications applications as Extensible Marku ...

uses (three hyphen-minuses) to end a section.

Command line

The hyphen-minus character is often used when specifying

command-line option A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

s, a convention popularized by

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

. Examples of the "short" form are -R or . A user can specify both by using -Rq. Some implementations allow two hyphen-minuses to specify "long" option names as or . These are easier to understand when reading commands (some software does not care about the number of hyphen-minuses, and either does not allow combinations of single-letter options, or requires the user to rearrange them, so they do not match a long option). A double hyphen-minus by itself (followed by a space) indicates that there are no more options, which is useful when one needs to specify a filename that starts with a hyphen-minus. An option of just a hyphen-minus (followed by a space) may be recognized

in lieu Many words in the English vocabulary are of French language, French origin, most coming from the Anglo-Norman language, Anglo-Norman spoken by the upper classes in England for several hundred years after the Norman conquest of England, Norman ...

of a filename and indicates that

stdin In computer programming, standard streams are preconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin), ...

is to be read.

output

is used to denote deleted lines in

diff In computing, the utility diff is a data comparison tool that computes and displays the differences between the contents of files. Unlike edit distance notions used for other purposes, diff is line-oriented rather than character-oriented, but i ...

output in the or the .

Encoding

The glyph has a

as . It is also in

with the same value.

Explanatory notes

References

External links

* {{DEFAULTSORT:Hyphen-Minus Punctuation Typographical symbols