What is logically wrong with the following program?
INPUT D, E
D = E / F
Print "The answer is" ; D 
End

Hello!
The simple answer to this question is that you are trying to divide by
zero.

Since you are attempting to divide E by F, qbasic wonders 'Where is
this F you're talking about?!'. Not finding it, it assigns a value of
0 to it.

Thus, the program you gave will show as:

INPUT D, E
D = E / 0
Print "The answer is" ; D

I believe what you meant to do was:

INPUT D, E
F = D / E
Print "The answer is" ; F

You may wish to do some simple syntax checking as well to make sure
the USER doesn't enter a 0.
With syntax checking the syntax would be:

INPUT D, E
if e > 0 then
  f = d / e
  print "The answer is "; F
else
  print "You cannot divide by 0!"
end if

Thanks!
Todd

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Clarification of Answer by coldfusion-ga on 17 Sep 2002 18:13 PDT

Oops the line that says:
if e > 0
should read:
if e <> 0 
Assuming you want to allow division by negative numbers.
Thanks

---

Clarification of Answer by coldfusion-ga on 17 Sep 2002 18:14 PDT

And just to summarize the answer to the exact question you posted:
It is logically wrong to try to divide by a variable that does not
exist, which causes division by 0.

If F is not defined, then isn't this the same thing as dividing by zero?

The program asks for the user to input variables d and e,
but then divides e by f (when f hasn't been defined, so will give a
'division by zero error')

Also, the program could also tell the user what it is doing, ie. the
program says "this answer is ', but it doesn't tell the user what the
calculation was, eg. it could say:

INPUT D,E
ANSWER=D/E
PRINT D;" divided by ";e;" is ";answer

So what it is doing which is logically wrong is:
In it's calculation it is using a variable that has not been defined (f)

ie. f has not been set to a value before e is divided by f