Without shift it's an en dash (–), with shift an em dash (—). Default X11 mapping for a German keyboard layout, zero config of mine.
LPT: on Android, pressing and holding a punctuation key on the on-screen keyboard reveals additional variations of it — like the em-dash, for example.
This is the №1 feature I expect everyone to know about (and explore!), but, alas, it doesn't appear to be the case even on Hackernews¹.
On Windows, pressing Win+. pops up an on-screen character keyboard with all the symbols one may need (including math symbols and emojis).
MacOS has a similar functionality IIRC.
And let's not forget that software like MS Word automatically correct dashes to em-dashes when appropriate — and some people may simply prefer typing text in a word processor and copy-pasting from it.
Anyway...
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¹ For example, holding "1" yields the superscript version, enabling one to format footnotes properly with less effort than using references in brackets², yet few people choose to do that.
² E.g. [2]
I've had a "trigger finger" for Alt+0151 on Windows since 2010 at least.
Em-Dash was really popular with professional writers.
Angled quotes I use only on systems on which I've configured a compose key, or Android when I'm typing Chinese.
I don't like any kind of auto-replacement with physical keyboards, so I turn off "smart quotes" on macOS.
Anyway I use characters like that all the time, but it's never auto-replace.
I am, it's on the default German X11 keyboard layout. Same for · × ÷ …
And that's without going to the trusty compose key (Caps Lock for me)… wonders like ½ and H₂O await!