感嘆符について

The exclamation mark ! (also known as exclamation point in American English) is a punctuation mark usually used after an interjection, an exclamation, a noise to indicate strong feelings (e.g. surprise, humour, anger), a loud sound (e.g. Bang!), or to show emphasis. The exclamation mark often marks the end of a sentence. A bare exclamation mark (with nothing before or after) is frequently used in warning signs.The exclamation mark likely came from the word io, used to show joy. Writers made a set of changes to io that made it become the exclamation mark. In the mid-14th century the Italian writer Iacopo Alpoleio da Urbisaglia created the exclamation mark since he was bothered when readers read emotional text without emotion.Other uses include:In mathematics, it denotes the factorial operation and shriek maps.Several computer languages use ! at the beginning of an expression to denote logical negation. For example, !A means "the logical negation of A", also called "not A". This usage has spread to ordinary language (e.g., "!clue" means no-clue or clueless).Some languages use ǃ, a symbol that looks like an exclamation mark, to denote a click consonant.In chess annotation, an exclamation mark after a move means that it is good; !! means it is excellent.