What happens when the initialization and condition parameters in the FOR loop are omitted?

Question

I've seen this case on quizzes and didn't know what the code stood for.

Answer 1

So what happens when there is no initialization and condition parameters in for loop. It looks like this:

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

In the case above, it is the infinite loop.
If "i" wasn't initialized above, you would get compile time error.

Answer 2

The for loop is something like
for (int i=0; i <10; i++){
//...
}

and that tells the compiler
int i =0 : here is the increment variable for the loop and it's initial value is 0. If you don't declare an incrementor, the compiler will accept that you don't need one.
i <10 : Run the for loop as long this boolean expression is true. If you omit that expression, the compiler will interprete that as true. Every time. The compiler hopes you know what your doing 😊
i++ : The increment (decrement is possible as well of course), that's just an example. Next time the loop runs the boolean expression mentioned above will be tested with the new incremented (or decremented) value. If you don't declare an incrementor, you cannot increment. So you are allowed to omit that, too.
So when you have
for ( ; ; )
you have an infinite loop.