Logical AND/OR/ Sequencing question

[CuriousOne]

Hello.

Say here is a logical structure like this

IF A=1 AND B<6 OR A=2 THEN

The first part is clear, if a=1 and b is less than 6, then do something
but what about OR?
when I add that OR A=2 this means B still should be less than 6, or that part is ignored and only A=2 is checked?

[HenrikOlsson]

AND, OR, XOR, ANDNOT, ORNOT, XORNOT all have the same precedence and so are evaluated from left to right. But, as the manual says:

Left-to-right is, in our opinion, unacceptable as a method of specifying the order of
evaluation. USE PARENTHESES to avoid ambiguity!

IF (A=1 AND B<6) OR (A=2) THEN makes it much clearer.

[aerostar]

OT

Have you got your HTC dot matrix ? on your other posting http://www.picbasic.co.uk/forum/show...445#post146445

[CuriousOne]

Nope, it is still on the way, will get it in week or so.

[CuriousOne]

So my question will be split into things like

IF A=1 AND B<6

OR B<6 AND A=2

I want to make it such way, than if A=2, then it would not care about whenever B is less than 6 or not.

[HenrikOlsson]

Have you TRIED it? Sometimes simply trying a few things out on your own gives you the answer much faster than asking here.

IF (A=1 AND B<6) OR (A=2) THEN
   LED = 1
ENDIF

Whenever A = 2 LED will turn on.
If A = 1 then B must also be <6 for LED to turn on.

Ugly and verbose but likely smaller:

IF A = 2 THEN LED = 1
IF (A = 1) AND (B < 6) THEN LED = 1

/Henrik.

[mpgmike]

Also, when using IF statements, it will probably take fewer lines of ASM code to execute if you put the clause most likely to give you a "yes", or the easiest to check first. IF (A = 2)... is the easiest to check so I'd put it first.