There Are Too Many Kinds Of Dashes:
So you've got the hyphen. That's the "-" guy. It joins words together. When you put "-ass" at the end of an adjective, you are using a hyphen. Also when you are separating out the syllables of a word, like for effect-"pre-pos-ter-ous"-that is also a hyphen job. The hyphen's function in that case is to make clear that these things are joined. The hyphen is an okay-ass punc-tu-a-tion mark.
Then there is what is called the "figure dash." That, too, is the "-" guy. It has the same meaning and use as the hyphen, but when you use it to connect numbers, rather than words or parts of words, you call it a "figure dash." Your phone number (555-123-4567) is connected by figure dashes. But let's be real, here: Those are just frickin' hyphens. The "figure dash" is bullshit.
Then, if you are a regular reader of this website, you likely know the "em dash," which several of us, most especially me, overuse badly. (My editor, who also overuses it, added two of them to the first paragraph.) That's the "-" guy. The long one. It has many uses, but mostly you will see it on either side of an interpolation-not an aside (which would be better marked with parentheses)-in the middle of a sentence. In writing that contains dialog, the em dash also is good for marking an interruption.
(Via Deadspin)
This is the first time I've really thought about the various dashes. I knew of them but not really the "official" uses of them, in so far as they are defined.
But wait!
And then, would you believe it, there is a whole other dash. This is the dreaded "en dash." The en dash is shorter than an em dash but longer than a hyphen. … The en dash does a bunch of stuff. It denotes a closed range or continuum of values … But it can also denote a relationship between two separate or even opposed things, like in a sports score … The en dash can also do other stuff. For example, it can help to sort out PEMDAS weirdness when you're sticking a prefix ("non-" for example) onto a phrase that is already compound and joined by a hyphen.
Thus, we have five different dashes (if you include the minus subtraction sign as a distinct character for mathematical equations, which I do) that we have to use. This is a mess.
I co-sign on this solution:
So what I am proposing is that there should be two kinds of dashes. There should be a short dash (-) and a long dash (-). The short dash can be for basically everything that you don't use an em dash for. The long dash can be for the em dash stuff. Ranges can just be short-dashed. Sports scores, too. Nobody is going to think that the Lakers defeated the Wizards by every number between 39 and 173. When I write that you are a goober-ass loser, nobody will wonder if what I mean is that you have somehow lost a coalition between the opposed forces of "goober" and "ass." It'll be fine.
The whole article is kind of fun, so read it for the silly sport-y examples.