It doesn't have to be a while loop. Recursion is another way to implement a loop with a priori unknown number of iterations. You can also use goto. And no, the

It doesn't have to be a while loop. Recursion is another way to implement a loop with a priori unknown number of iterations. You can also use goto. And no, they aren't othogonal. A simple language with only integer variables, basic arithmetic, if() and for(i in range(x,y)) is actually not Turing complete.