Hyphen-minus
- | |
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Hyphen-minus | |
In Unicode | U+002D - HYPHEN-MINUS |
Different from | |
Different from | U+2010 ‐ HYPHEN U+2011 ‑ NON-BREAKING HYPHEN |
The hyphen-minus symbol - is the form of
Description
-+− -+− | |
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hyphen-minus, plus, and minus signs in proportional and monospaced fonts |
In early
In most modern computer fonts, the hyphen-minus is either identical or very similar to the Unicode hyphen.[6][a]
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.[b]
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
Programming languages
Most programming languages use the hyphen-minus for denoting subtraction and negation.[9][10] It is rarely used to indicate a range, due to ambiguity with subtraction. Generally, other characters, such as the Unicode U+2212 − MINUS SIGN are not recognized as an operator.[citation needed]
In some programming languages (for example MySQL) --
(two hyphen-minus) mark the beginning of a comment. It can be used to start the signature block in Usenet news system. YAML uses ---
(three hyphen-minuses) to end a section.
Command line
The hyphen-minus character is often used when specifying
diff
output
-
is used to denote deleted lines in diff output in the context format or the unified format.
Encoding
The glyph has a code point in Unicode as U+002D - HYPHEN-MINUS. It is also in ASCII with the same value.
See also
- -- (disambiguation)
- Box-drawing charactersincluding ─ (U+2500), useful for drawing horizontal lines
- Hyphen
- Soft hyphen
Explanatory notes
References
- ISBN 978-0-596-10121-3.[dead link]
- ^ "3.1 General scripts" (PDF). Unicode Version 1.0 · Character Blocks. p. 30. Archived (PDF) from the original on 21 November 2021. Retrieved 10 December 2021.
Loose vs. Precise Semantics. Some ASCII characters have multiple uses, either through ambiguity in the original standards or through accumulated reinterpretations of a limited codeset. For example, 27 hex is defined in ANSI X3.4 as apostrophe (closing single quotation mark; acute accent), and 2D hex as hyphen minus. In general, the Unicode standard provides the same interpretation for the equivalent code values, without adding to or subtracting from their semantics. The Unicode standard supplies unambiguous codes elsewhere for the most useful particular interpretations of these ASCII values; the corresponding unambiguous characters are cross-referenced in the character names list for this block. In a few cases, the Unicode standard indicates the generic interpretation of an ASCII code in the name of the corresponding Unicode character, for example U+0027 is APOSTROPHE-QUOTE'.
- ^ "American National Standard X3.4-1977: American Standard Code for Information Interchange" (PDF). National Institute of Standards and Technology. p. 10 (4.2 Graphic characters). Archived (PDF) from the original on 9 October 2022. Retrieved 10 December 2021.
- ^ "The Unicode Standard, Version 13.0, Chapter 6.2" (PDF). 2020. General Punctuation § Dashes and Hyphens. Archived (PDF) from the original on 22 January 2021. Retrieved 30 December 2020.
- ^ Korpela, Jukka. "Dashes and Hyphens § Typographic Usage". Archived from the original on 26 January 2021. Retrieved 30 December 2020.
- ^ Marian, Jakub. "Hyphen, minus, en-dash, and em-dash: difference and usage in English". Archived from the original on 25 December 2020. Retrieved 23 December 2020.
A hyphen is usually very short (it has its own Unicode character, but you can use the hyphen-minus instead because it looks the same) ...
- ISBN 9780321385444. Retrieved 4 July 2020.
- ISBN 978-0-88179-206-5. Retrieved 10 November 2020.
In typescript, a double hyphen (--) is often used for a long dash. Double hyphens in a typeset document are a sure sign that the type was set by a typist, not a typographer. A typographer will use an em dash, three-quarter em, or en dash, depending on context or personal style. The em dash is the nineteenth-century standard, still prescribed in many editorial style books, but the em dash is too long for use with the best text faces. Like the oversized space between sentences, it belongs to the padded and corseted aesthetic of Victorian typography.
- ^ Ritchie, Dennis (c. 1975). "C Reference Manual" (PDF). Bell Labs. Archived (PDF) from the original on 3 April 2017. Retrieved 7 December 2016.
- ^ Marlow, Simon (ed.). Haskell 2010 Language Report (PDF). Archived (PDF) from the original on 4 December 2016. Retrieved 7 December 2016.[page needed]
External links
- The dictionary definition of - at Wiktionary