Exclamation mark

An exclamation mark (!) is a punctuation mark. It is used to show strong emotion at the end of a sentence or after an interjection.^[1]

Putting a space before an exclamation mark is incorrect.

In coding, "!" sometimes means not. In mathematics, the use of an exclamation mark can be used for the factorial function (for example, ${\displaystyle n!}$).^[2][3][4]