Dash
| Punctuation marks |
|---|
|
apostrophe ( ' ) parentheses ( ( ) ), brackets ( [ ] ); ( { } ); ( < > ) colon ( : ) comma ( , ) dash ( ‒ ); ( – ); ( — ); ( ― ) ellipsis ( ... ) exclamation mark ( ! ); ( á ! ) full stop/period ( . ) hyphen ( - ); ( ‐ ) interrobang ( ‽ ) question mark ( ? ); ( ÿ ? ) quotation marks ( ‘ ’ ); ( “ ” ); ( ‹ › ); ( ë û ); ( ‚ ‘ ); ( „ “ ); ( àà); ( 「 」 ); ( 『 』 ) semicolon ( ; ) slash ( / ) and backslash ( \\ ) space ( ) and interpunct ( ÷ ) vertical bar / pipe ( | ) asterisk ( * ) and dagger ( àà) |
A dash is a punctuation mark, and is not to be confused with the hyphen, which has quite different uses.
Common dashes
Several forms of dashes exist, of which the most common are:
Figure dash
The figure dash (‒) is so named because it is the same width as a digit—in fonts with digits of equal width. This dash is used when a dash must be used within numbers, for example with telephone numbers: 634‒5789. Note that this does not indicate a range (use an en dash instead), or function as the minus sign (which has its own glyph). Use the numeric forms ‒ or ‒ to type it; there is no equivalent HTML entity.
Minus sign
The minus sign (−) is an arithmetic operator. This character is used only in mathematical formulas and equations, and it is usually designed to be the same length and height as the plus and equals signs. In most fonts these are usually monospaced along with the numbers for ease when being used in tabular formats. Use the HTML entity − to type it, or the numeric forms − or −.
It is used to indicate a closed range, or a connection between two things of almost any kind: numbers, people, places, etc.. Examples:
It indicates a sudden break in thought—a parenthetical statement like this one—or an open range ("John Doe, 1987—"). The em dash is used in much the way a colon or set of parentheses is used: it can show an abrupt change in thought or be used where a period is too strong and a comma too weak.
In North American usage—and also in old British usage—an em dash is never surrounded by spaces. In contrast, the modern practice in Europe and Australasia — and, indeed, many other parts of the English-speaking world — is to separate the dash from its surrounding words when used parenthetically, by using spaces or hair spaces (U+200A). (Note that hair spaces may not display in most user agents.) Some writers eschew the use of the em dash – instead, they replace it with the shorter en dash – which is then also surrounded by spaces or hair spaces; this "space, en dash, space" sequence is also the predominant style in German typography.
When an actual em dash is unavailable, a doubledash ("--") can be used to distinguish from a hyphen in American English. However, this has never been accepted in other variants, such as Commonwealth English, and the same method as when using an en dash could be used instead (namely, " - "). A better use, if possible, would be to use the HTML entity — or the numeric forms — or —.
Modern computer software, however, typically has a much expanded character set and is usually perfectly capable of rendering both the en and em dashes correctly—albeit with a little inconvenience.
The HTML entity names for the em dash and the en dash are — and –. The equivalent HTML numeric character entity references are — and –. Nearly all web browsers and operating systems used today are capable of rendering the numeric form, and almost as many correctly display the named form.
In Unicode, the figure dash, en dash, em dash, quotation dash, and swung dash correspond to characters U+2012, U+2013, U+2014, U+2015, and U+2053, respectively.
Under Mac OS X, an em dash can be obtained in any application by typing shift-option-dash. An en dash can be obtained with option-dash.
In TeX, an em dash is typed as three hyphens ("---"), an en dash as two hyphens ("--"), and a hyphen as one hyphen ("-").
In Microsoft Word, an em dash will be produced by Autocorrect when two hyphens are entered between words ("word--word"). An en dash is produced by two hyphens surrounded by spaces ("word -- word"). More directly, an em dash can be typed with ctrl+alt+numeric hyphen (on the numeric keypad, usually in the top right corner), and an en dash can be typed with ctrl+numeric hyphen. Note that it will not work with the hyphen key on the main keyboard (usually between "0" and "="), which has completely different functions associated with these commands. Other dashes, spaces, and special characters are possible, found through Tools -> Customize... -> Keyboard... -> Common Symbols. Unassigned symbols (such as the true minus sign) can be assigned to shortcuts (such as ctrl+shift+numeric hyphen) through Insert -> Symbol... -> (select desired symbol) -> Shortcut key...
In professionally printed documents, the typographer sometimes adds a hair space on either side of an em dash (a refinement that is not practicable in electronic form given the limitations of current-generation web browsers) or even a full space, though this last is uncommon.En dash
The en dash (–) is one in width: the width of the capital N in any particular font. The en dash is by definition exactly half the width of an em dash.
You would also use an en dash when you have a compound adjective, one part of which consists of two words or a hyphenated word:
An en dash correctly does not have spaces around it; however, when an actual en dash is unavailable, use a dash with single spaces (" - ") to distinguish from a hyphen; or (better) use the HTML entity – or the numeric forms – or –, in either case without spaces around it.Em dash
The em dash (—) is defined as one in width: the width of the capital M in any particular font. By definition the em dash is twice as wide as the en dash in any particular font.En dash versus Em dash
Some people prefer to use an en dash instead of an em dash for parenthetical statements. A spaced en dash is commonly used for this purpose in British publications, whereas in the USA the tendency is to use the unspaced em dash. However, it is sometimes argued that using an en dash here can lead to confusion, on the grounds that the dashes have different semantic meanings.Quotation dash
The quotation dash or horizontal bar (―) is used to introduce quoted text. In most fonts it is rendered identically to the em dash, which can also be used. Since browser support for it is nearly non-existent and Unicode itself equates use, in Wikipedia use the em dash instead. It can be typed only with the numeric form, ― there is no equivalent HTML entity.Swung dash
The swung dash (⁓) resembles a lengthened tilde, and is used to separate alternatives. In dictionaries, it is frequently used to stand in for the defined term in example text. In mathematics, it is used to show similarity, equivalence, or asymptotic relations.Summary
To summarize the above:See also
Wikipedia:Manual of Style#DashesOther dashes and dash-like characters
Rendering dashes on computers
Typewriters and computers have traditionally had only a limited character set, often having no key with which to produce a dash. In consequence, it became common to substitute the nearest incorrect punctuation mark or symbol. Em dashes are often represented by a pair of spaces surrounding a single minus sign (typical British usage) or by a pair of spaces surrounding two minus signs (mostly in the United States).