Apple - How to type a long/em dash `—`

This might be one of those that changes by language, but on a UK English keyboard [& from comments, also US English], there are 4 dashes available from the key to the right of 0, Minus.

- - key alone (hyphen)
– - Opt ⌥ (en dash)
— - Opt ⌥ Shift ⇧ (em dash)
_ - Shift ⇧ (underscore)

Late Edit...
To complete the set, & from comments...

Ctrl ⌃ Opt ⌥ - will give 'information separator one' which looks like a space "" & doesn't even seem to print in here. You could, however use the keyboard replacement tool to turn that into a true minus sign... −

After some digging around I've found that Alt+Shift+Minus renders the long/em dash (—) character.