Thanks a lot, Ralph and Bob.
I think, I've got it.
Thomas
Am 04.01.2018 um 22:57 schrieb Bob Sneidar via use-livecode:
In short, yes. Commands can still pass parameters, and as you may not know CAN
ALSO RETURN VALUES. The difference is that functions are called with
parenthesis and must be put into a variable. eg.
function bobtest 1, 2
-- do some stuff
return true
-- do some other stuff
end bobtest
Now I can say:
put bobTest(1, 2) into tBobResult -- if you exclude into tBobResult the result
will be put into the message
Commands are simply called and then the result variable contains anything put
there by the return command ie.
on bobtest2 pParam1, pParam2
-- do some stuff
return true
-- do some other stuff
end bobtest2
Now I can say:
bobtest 1,2 -- or dispatch "bobtest" to card 1 with 1,2
put the result into tBobResult
NOTE: when a return command is encountered, either in a command or function,
the handler is immediately exited and control is returned to the calling
handler. So anything after -- do some other stuff WILL NOT EXECUTE.
I suppose the difference may be somewhat academic, but as a convention, functions are
usually used to get information, process it and return values without actually
"doing" anything, like going to a card or putting values into fields etc.
Commands actually DO things, but nothing is preventing you from using all commands or all
functions. You can see though from the above examples that functions are slightly simpler
to code with, requiring one line instead of two to process returned values. It can also
make code more readable:
put theInternetDate(the date) into tToday
updateTheRecordDate tToday
Bob S
On Jan 4, 2018, at 13:30 , Thomas von Fintel via use-livecode
<use-livecode@lists.runrev.com> wrote:
I am well aware that I shouldn't expect *everything* in Livecode to be
intuitive, but this one bugs me:
Having a handler like
function DoStuff_1 a, b
return a
end DoStuff_1
When you do "put DoStuff_1 (2,3)" the result is 2.
But with
on DoStuff_2 a, b
put a
end DoStuff_2
The result of DoStuff_2 (2, 3) is 2,3. "put a*b" produces an error.
This means, parameters are passed differently to command handlers and function
handlers. Right?
Is that the way it should be and why?
Thanks for your patience
Thomas
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