In almost, if not every, programming language, pressing ctrl+c cancels your code. Why does it specifically have to be ctrl+c? So in other words, what made the developers of programming languages decide that ctrl+c has to be the combination to cancel the code and cause an error?
It doesn't "have to be" anything, it is a convention formed over a long history: Control-C, "C" for cancel, was I think first used in TOPS-10, a Digital Equipment Corporation (DEC) mainframe operating system used in the late 1960s. The control key itself goes back much further, used on telegraphs and teletypewriters to key in non-printing characters. The idea of non-printing characters controlling a machine without sending a message has an even longer history, including procedure signs in Morse code, "NUL" and "DEL" in Baudot code, and other late 19th-century teleprinter standards and their devices.
Why does ctrl+c have to be the combination to cause an error (e.g. KeyboardInterrupt)?