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replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 1:05 pm
by glenn9
Hi,
I'm trying to replace a mathematical operator (+, *, -, /) with a variable but LC doesn't seem to like it!
Not sure where I'm going wrong with the logic!
Code: Select all
local tANumber, tOperator, tAnotherNumber
-- instead of: put value(1 + 2) into field 1, I tried this
put value(tANumber tOperator tAnotherNumber) into field 1
grateful for any advice
Kind regards,
Glenn
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 1:53 pm
by Klaus
Hi Glenn,
this will work with a tiny "detour":
Code: Select all
...
put 10 into aNum
put "+" into tOperator
put 22 into tNum2
put (aNum & tOperator & tNum2) into aVar
put value(aVar)
## -> 32
...
Best
Klaus
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 2:09 pm
by dunbarx
What Klaus said.
The "value" function evaluates an entire string as a package.
Tbe only other way I can see doing this (rather odd) thing is:
Code: Select all
on mouseUp
put "+" into tPlus
do "answer 42" && tPlus && "42"
end mouseUp
Sort of the same thing, LC being asked to perform an additional level of evaluation on a prepared string.
Craig
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 2:47 pm
by glenn9
Klaus, Craig,
Brilliant, it works - thanks!
(the background is that I'm trying to teach my daughter some LC through building a mental arithmetic training app, and wanted to be able to change the operator through a comboBox choice, so had to have the operator as a variable!)
Thanks again,
Regards,
Glenn
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 3:11 pm
by dunbarx
Cool.
But isn't that a rather advanced concept for a newbie LC student? Unless she is in fact rather well along....
Craig
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 4:12 pm
by glenn9
We've done simple comboboxes & variables before... and I thought just swapping an operator for a variable would easily work.....!
having said that I'm still finding LC so much more enjoyable and understandable as a hobby coder than even python...
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 4:44 pm
by dunbarx
Task her to build an app. Any kind of app, an address book or something that converts millimeters to tons. I often say that it does not matter how trivial the app seems, the exercise itself will not be.
Craig
Re: replacing mathematical operators with a variable
Posted: Mon Mar 09, 2020 10:59 pm
by bogs
dunbarx wrote: ↑Mon Mar 09, 2020 2:09 pm
Tbe
only other way I can see doing this (rather odd) thing is:
Code: Select all
on mouseUp
put "+" into tPlus
do "answer 42" && tPlus && "42"
end mouseUp
Craig
Code: Select all
put 1 into tANumber; put 5 into tAnotherNumber; put "+" into tOperator
put value(tANumber & tOperator & TAnotherNumber)