name look up of 'x' changed for new ISO 'for' scoping

Projects Programming
1

can someone please explain the meaning of this error for me or direct me to a link that explains it.

2

If you provided the code and the exact error messages, then maybe.

3

I'm guessing that you have something like:

for(int i=0; i<10; i++)
{
}
Serial.print(i);

The variable i is local to the for loop. Referencing it after the loop ends is (now) illegal.

4

yes ok i just dont understand why.

5

i just dont understand why.

You don't understand why what?
Why the variable goes out of scope?
Why it's illegal to access a variable that is out of scope?
Why the rules were changed to make access to out-of-scope for loop variables illegal?

6

option 3.

7

If you need some help with the concept of scope, check out post #2 at:

http://forum.arduino.cc/index.php?topic=253801.msg1796184#msg1796184

8

Are you familiar with the Monty Python "Dead Parrot Sketch"? After it goes out of scope a variable is dead, pining for the fjords.

9

It's like trying to talk to someone who has left the room. They are not in the "scope" of the room any more.

10

arduidiot:
option 3.

Because the rules were awful and made code fragile to cut/paste induced name collisions?

11

PaulS:
I'm guessing that you have something like:

for(int i=0; i<10; i++)

{
}
Serial.print(i);

There's an easy work-around:

int i;
for(i=0; i<10; i++)
{
}
Serial.print(i);

Now "i" is in scope after the loop.