Dash (-)

The dash (-) is a punctuation mark that is similar to a hyphen or minus sign, but differs from both of these symbols primarily in length and function. 

Learning about the various dashes

A dash (-) is a punctuation mark used primarily for separating parenthetical statements from the main sentence of an article. While a dash might resemble a hyphen or minus sign at quick glance, it is longer. Depending on the typeface, a dash might also be thinner and slightly higher above the baseline of text.

The two most common dash variants are the en dash (–) and the em dash (—). The keypad codes for these dashes are as follows:

• en dash: alt+0150
• em dash: alt+0151

Either dash is appropriate for parenthetical sentence breaks, but as a general rule, the en dash should be used with spaces and the em dash without:

Stallone's attempts at comedy – Oscar; Stop! Or My Mom Will Shoot – were huge disappointments at the box office.

Shades of red—crimson, maroon, ruby—tend to pair with black much better than shades of green.

Inserting the punctuation into sentences

When it comes to ranges of value or spans of dates and time, the en dash (but not the em dash) is often used in place of the word "to":

During Jimmy Carter's 1977–1981 presidency, brutal dictatorships were toppled in Cambodia, Iran, and Nicaragua.

The Portland Trail Blazers overcame a 2–0 series deficit and ultimately won 109–107 over the Philadelphia 76ers in Game 6 of the 1977 NBA Finals.

Had the ship been properly equipped for such an emergency, all the passengers and crew could have boarded lifeboats during the 11:39 PM–2:20 AM sinking of the RMS Titanic.

The word "to" should not be supplanted by an en dash in sentences where the numbers in question are preceded by the word "from." Example: Jimmy Carter served as President from 1977 to 1981.

The em dash (but not the en dash) is used to link sources to block quotes within texts.

"The great thing about rock and roll is that someone like me can be a star." — Elton John.

Further rules and examples for incorporating the dash

The em dash allows for better organization within texts because it distinguishes parenthetical passages from in-text citations. 

According to one witness—who lives in the building kitty-corner from where the bomb exploded—the smoke was "pouring out of the [windows] and people were running for safety as [fire crew] did their thing," (Richards and Hodge).

As the above example shows, the use of different punctuation marks for parenthetical detail, quote modifications, and source attribution makes it easier to tell them apart than it otherwise would have been had parentheses been used for each function.

Dashes also make it possible to condense vast amounts of detail on a subject into a few sentences, as the following paragraph demonstrates:

The 1975–1980 period saw Phil Collins—newly promoted to the vocalist role in Genesis following the departure of Peter Gabriel—at his most creative. Not only did his band deliver three of its finest albums—A Trick of the Tail, Wind and Wuthering, and Duke—he also provided vocals on two folk-classical songs—"Which Way the Wind Blows" and "God If I Saw Her Now"—by the band's 1968–1970 guitarist Anthony Phillips. Additionally, the diminutive multi-talent flexed his drumming chops on a string of 1976–1979 albums—Unorthodox Behavior, Moroccan Role, and Product—with the jazz-fusion ensemble Brand X.

Confusion could arise if more than one parenthetical passage is inserted into a single sentence, but the options afforded by dashes can be mighty useful when character space is limited and information must be delivered with a minimum of words.