Hmm.

While your observation is possibly correct, it is not useful for coding.

Consider the situation where you get user input and want to validate it. I used this just recently in an example to check a users keypress.

code:
Get $cKey
If InStr("YN",$cKey)
   "User typed a valid key" ?
Else
   "Please only hit the Y or N key." ?
Fi
If your user managed to get a null entry returned, the value (-1) would equate to TRUE and give a false result.

Also, don't forget that the value returned is the start position of the first instance of the string, not every instance so an "everywhere" value is not correct, but the first time the null string appears is before the first character of the string, which is of course character position zero [Wink]