I take the point about other basics doing it differently, but this is how
Sinclair BASIC has worked, by building up a value for the overall expression
through splitting up and building up to the final logcal value. The easiest
way around this simple example is using two IFs instead of AND to ensure
(b/a) is never executed (or am I missing something here?)
10 a=0
20 b=10
30 IF a<>0
35 IF (b/a)=5
40 do_something
50 END IF
60 END IF
I agree though, the way you would like it to work would obviously be better.
Dilwyn
-----Original Message-----
From: Wolfgang Lenerz via Ql-Users
Sent: Tuesday, September 19, 2017 8:27 PM
To: ql-us...@q-v-d.com
Cc: Wolfgang Lenerz
Subject: [Ql-Users] Stupid AND
Hi all,
Just a rant about the SBasic AND operator.
Suppose this:
10 a=0
20 b=10
30 if (a<>0 AND b/a=5)
40 do_something
50 end if
Run it and what happens?
You get an "overflow" error at line 30.
You get this error because it is trying to evaluate the second condition
(b/a) and failing as a=0 and you can't divide by 0.
BUT WHY IS IT TRYING TO EVALUATE THE SECOND CONDITION IN THE FIRST PLACE?
The first condition (a<>0) is NOT met and so, in any other programming
language I use, the second condition isn't even tested, as the result
will be "false" anyway because of this.
Apparently though, Sbasic still also tests the second condition.
Grrrr.
Wolfgang
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