Followed by a variable or an expression, and GOTO or GOSUB, arranges for jumping to different parts of a program according to the value from the variable or expression
Implemented by: dartmouth4, ansimin, ansifull, altair8K, Applesoft, cbmv7, Simons1, level2, trscolor, BBC, VBDOS
With variations: ti994ext (added ON WARNING, ON BREAK, ON ERROR without GOTO or GOSUB), GWBASIC, MSX (used with INTERVAL, KEY, SPRITE, STOP and STRIG followed by GOSUB), QBasic (also with COM, KEY, PEN, PLAY, STRIG and TIMER), qb4.5 (added ON UEVENT), ugBASIC (as ON SCROLL..CALL , ON SCROL..GOSUB and ON..PROC)
Also written as: