having some syntax difficulty... I'm new to this

[rto0288]

CLS
FOR I = 0 to 500
PRINT I; CHR$(I); " ";
NEXT I

I read this almost verbatim from a tutorial and it's not working... gives me an illegal function call on the PRINT line.

--ALSO--

I'm having problems with the LOCATE command. I'm trying to use variables for my locate coordinates and it's giving me illegal function call on locate line. I do something like this:

CLS
x=1
y=1
DO
LOCATE x, y
PRINT x;
x=x+1
y=y+1
LOOP

>>this won't work for me...

[Mikrondel]

Well first I commend you for explaining the problems well.

Now; a bit of testing is in order.

The "Immediate" window is where you type a line, and it gets executed as soon as you press enter. This lets you check things without having to modify your program. Say you Ctrl-Breaked out of something, (or an error kicked you out) you can use the immediate window to, for example, check what the variables were.

For the first program: run it (get the error), then go into the Immediate window and type
PRINT I
You should get the number 256 on the screen.

Ok, so maybe CHR$(256) doesn't work? Try
PRINT CHR$(256)
And there's your error.
OK, so you can only use CHR$ for numbers between 0 and 255. This is because all printable characters are 1 byte; 1 byte can store integers from 0 to 255. ASCII is the system which connects each of those numbers to a symbol.
CHR$() is a function that returns an ASCII character, and is only defined for numbers from 0 to 255 - otherwise you get an illegal function call.

Anyway, change your FOR-loop to suit this limit.


As a side note, a few characters of ASCII value between about 7 and 13 interfere with what's being displayed - e.g. CHR$(12) clears the screen, I think.


Now, onto the second program. Similar issue. X and Y get out of the range that LOCATE supports. (Normally the screen is 80x25 or 80x50)

Because your DO-LOOP goes on indefinitely, x and y will keep getting larger until an error occurs.

As another side note, since in your second program x and y are always the same, you can get rid of anything involving y altogether, and just

LOCATE x, x

with exactly the same result (but a simpler and more efficient program).


I'm working (very slowly, unfortunately. Extremely busy with school right now) on a tutorial that you may like to look at: aleks.budzynowski.info/wiki/quickbasic/tutorial/index