Question

Is there any difference code-wise between:

int i = 0;
for ( i = 0 ; i < n ; i++ )
{
}

and

for ( int i = 0 ; i < n ; i++ )
{
}

Maybe if there are more loops and they all use the same index?

Also, is the first version equivalent to:

int i = 0;
for ( ; i < n ; i++ )
{
}

I know the optimizer should be smart enough to generate the same code at least, but is there theoretically any difference?

Answer 1

Ok so I figured out why we were using the index declaration outside the loop.

Apparently our solaris compiler will give a compilation error for code like:

for ( int i = 0 ; ; );
for ( int i = 0 ; ; );

The error is:

Error: multiple declaration for i.