Why does a for-loop stop at the correct place when you use the same counter name as your upper limit?

Why does this code work, and display the numbers 1-7, rather than stopping at r=1 or going on infinitely (for each step, r=r and the loop continues)?

r=7;
for r=1:r
  disp(r)
end

Answer 1

[Ahmet Cecen]

Because the upper limit is evaluated at the beginning of the execution when r = 7. If you want the loop condition to be evaluated every time the loop iterates, you need to use a while loop. See even if you did something like this:

r=7;
for r=1:r
    r=5;
    disp(r)
end

You would still get 7 iterations. However now we are overwriting the iterator so you would only get 5s.