Why is 'continue' statement ignoring the l

Question

Why does it tend to get into an infinite loop if I use continue in a while loop, but works fine in a for loop?
The loop-counter increment i++ gets ignored in while loop if I use it after continue, but it works if it is in for loop.

If continue ignores subsequent statements, then why doesn't it ignore the third statement of the for loop then, which contains the counter increment i++? Isn't the third statement of for loop subsequent to continue as well and should be ignored, given the third statement of for loop is executed after the loop body?

while(i<10)   //causes infinite loop
{
    ...
    continue
    i++
    ...
}

for(i=0;i<10;i++)  //works fine and exits after 10 iterations
{
    ...
    continue
    ...
}

Answer 1

In any loop, continue moves execution back to the top of the loop, not executing any other instructions after the continue statement.

In this case, the for loop's definition is always executed (per standard C), whereas the i++; statement is NOT executed, because it comes AFTER the continue statement.

Answer 2

continue bypasses the rest of the block and begins again at the top of the block if the conditional of the loop is met.

The next question is: "What do I do, then?" There are two answers I can think of.

Example:

void foo ()
{
    size_t i = 0;
    do
    {
        /*...*/
        if ( /*...*/ )
        {
            /*...*/
            continue;
        }
        /*...*/
        i++;
    } while ( /* loop conditional */ );
}

Solution #1: Manually Increment

void foo ()
{
    size_t i = 0;
    do
    {
        /*...*/
        if ( /*...*/ )
        {
            /*...*/
            i++;
            continue;
        }
        /*...*/
        i++;
    } while ( /* loop conditional */ );
}

Solution #2: A uniquely valid application of goto*

void foo ()
{
    size_t i = 0;
    do
    {
        /*...*/
        if ( /*...*/ )
        {
            /*...*/
            goto foo_next;
        }
        /*...*/
foo_next:
        i++;
    } while ( /* loop conditional */ );
}

goto is valid in this case because incrementation in two places is technically the same instruction. This solution is especially relevant when the per-iteration-volatile variables are more complex; such as, setting multiple variables or modifying a value with an equation or function.

In the event of a single increment or decrement statement, Solution #1 may prove favorable; however, it should be noted that: if the code is modified after such an implementation, one must remember to update both instances of the statement (which may be prone to bugs, especially if the modifications take place after an extended period of time**). Therefore, I highly reccomend Solution #2.

*Some consider any and all use of goto bad practice. I recommend you decide for yourself, and leave you this: google for "c goto bad"

**A comment reminding of this necessity may suffice, but — if my advice has been followed — the per-iteration-volatile variables in are restricted to a single statement. And I quote:

There is never a reason to comment a single line

-Linus Torvalds (source: http://yarchive.net/comp/linux/coding_style.html)