Ever think about what kind of dash you need?
Em dashes are the size of an “M” … maybe fun to remember it with the performer Eminem … two M’s in there. Em dashes are used to give a strong separation in a thought that you still want to keep connected. A semicolon can also perform this function, but an em dash does it in a more — pronounced way.
En dashes are the size of an “N” … maybe fun with a song memory too … “na na na na … hey, hey it’s smaller than an em dash!” En dashes are typically used to represent a span or range for numbers, dates, or the like. They are often interpreted to be used to mean “to” or “through.” Like … “I’m travelling to Hawaii and away Jan. 1, 2018–Jan.15, 2018.”
Hyphens are the shortest of these dashes and they are primarily used to help form compound terms. “Copy-Editing for you is a blast!”
Of course … use of these dashes and whether you put spaces around them may also be dictated by the style guide(s) you may be working with.