switches on a message, so that it can be printed.
switches on a named group of messages.
switches on tracing for the symbol s.
switches on several messages or message groups.
- Some messages for built-in functions are off by default, and must explicitly be switched on using On.
- In On["name"], possible named message groups include:
"Compiler" warnings associated with compiled code "Graphics" warnings associated with graphics generation "Packing" notifications associated with packed arrays "Spelling" spell-checking messages for symbol names "Symbolics" warnings associated with symbolic computation
- $MessageGroups gives a complete list of message groups recognized by On.
- On[General::name] switches on all messages derived from General::name.
- When tracing is switched on, each evaluation of a symbol, on its own or as a function, is printed, together with the result.
- Note that the tracing information is printed when a function returns. As a result, traces of recursive functions appear in the opposite order from their calls.
- On[Assert] switches on messages associated with assertions specified by Assert.
- On[s] is equivalent to On[s::trace].
- On is equivalent to On[s::trace] for all symbols.
Wolfram Research (1988), On, Wolfram Language function, https://reference.wolfram.com/language/ref/On.html (updated 2010).
Wolfram Language. 1988. "On." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2010. https://reference.wolfram.com/language/ref/On.html.
Wolfram Language. (1988). On. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/On.html