Steven D'Aprano <st...@remove-this-cybersource.com.au> writes: > On Sat, 17 Apr 2010 12:05:03 +0200, Alain Ketterlin wrote: > >>> I don't know of any language that creates a new scope for loop >>> variables, but perhaps that's just my ignorance... >> >> I think Pascal and Modula-2 do this, Fortran does this, as well as Ada. > > Pascal doesn't do this. [...] > for i := 1 to 3 do > begin > writeln(i); > end; > writeln(i); [...]
At http://standardpascal.org/iso7185.html#6.8.3.9%20For-statements (sorry, I didn't find a more readable version), I read (second paragraph, fourth sentence) : "After a for-statement is executed, other than being left by a goto-statement, the control-variable shall be undefined." So, at least, the compiler should emit a warning. > However you can't assign to the loop variable inside the loop. Outside of > the loop, it is treated as just an ordinary variable and you can assign > to it as usual. I read the excerpt above as: you have to re-assign to it before using it. The corner-case is obvious: if the loop body is not executed at all, you cannot assume the "control-variable" will have the first value. I'm curious to know what gets printed if you swap 1 and 3 in the above code. -- Alain. -- http://mail.python.org/mailman/listinfo/python-list
