Question

I noticed a strange behavior of a for cycle…

Case 1:

Let us have an internal initialization of i variable

for ( int i=10; i <=10; i++)
{
    std::cout << i;
}
return 0;

Output:

10

Case 2:

Now we initialize i outside the cycle

int i = 10;

for ( ; i <=10; i++)
{
    std::cout << i;
}
return 0;

Output:

Nothing will be print

Case 3:

Initialization any variable not related to i:

int i = 10;

for ( int k = 0 ; i <=10; i++)
{
    std::cout << i;
}
return 0;

Output:

10

Question

How can depend a result of a cycle condition on the place where we initialize variable i?

Updated results

I traced a code using degugger and VS 2010 really jumps over a cycle in case 2.
However g++ works well.
Maybe a bug in compiler?

Fianal results
After reboot it works correcly. Something between heaven and earth.
Sorry for the useless question….

Answer 1

If case 2 doesn’t print 10 you have a bug in your compiler or the output isn’t being flushed. Add a << "\n" to the output as well.