[gmrple]

He is not right either... 15 is 0xF. 16 is 0x10.

[fr0sty]

He is correct, that the value 16 given to MID$ as a 'start' will yield an "F" because the 'start' argument to the MID$ function is one-based.

This is the string:

     A$ = "0123456789ABCDEF"

And calling the function will give you: MID$ (A$,1,1) => "0" ... MID$ (A$,15,1) => "E" MID$ (A$,16,1) => "F"

MID$ (

[Falling3]

Ah, thanks! I was scratching my head on that one...

[acegopher]

Right, the reason it won't ever emit F is because RND(1) will never return 1, it's implementation will return 0<=X<1, and INT() is a truncation, so INT(RND(1) + 15) will return an integer between 0 and 14. Adding one gives 1 to 15, and since F is in the 16th position of the string (Apple BASIC indexed from 1, not 0) it will never get selected.

[jamesbrownuhh]

INT(RND(1)+15) will always return 15 and nothing else, since the expected output would be a rounded-down integer value of (a random number between 0 and 0.99999999etc999, plus 15).

INT(RND(1) * 15), in contrast will produce a random whole number from 0 to 14. Hence the popular use of, for example, INT(RND(1) * 6)+1 in any given situation where a random number between 1 and 6 is required.

[acegopher]

Correct... my mistake, I put "+" when the original code was "*".

[delinka]

But they're using MID to extract a character from the string. Seems to me that string indexes are 1-based in Apple BASIC as evidenced by the " ... + 1" and the fact that there are 0's on the page. So you select from characters 1 to 16 in the string.

Edit: seems I was slower than all the other replies...