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A punctuation mark (!) used after an abrupt and emphatic statement or after a command: “‘Help!’ he cried, as his boat floated toward the edge of Niagara Falls.”
The character "!" with ASCII code 33.
Common names: bang; pling; excl (/eks'kl/); shriek; ITU-T: exclamation mark, exclamation point (US). Rare: factorial; exclam; smash; cuss; boing; yell; wow; hey; wham; eureka; soldier; INTERCAL: spark-spot.
The Commonwealth Hackish, "pling", is common among Acorn Archimedes owners. Bang is more common in the USA.
The occasional CMU usage, "shriek", is also used by APL fans and mathematicians, especially category theorists.
Exclamation mark is used in C and elsewhere as the logical negation operation (NOT).