Hi again
In this post you will find a very very simple example of a Do Until.
Now, imagine you initialize an integer variable 'i' as 0. You also initialize a boolean variable 'exit' as false. Then you enter the loop, inside it:
-inspect the content of the i'th element of the array
-decide if for some reason we shall stop evaluating array items, if so set 'exit' as true;
-finally increment the integer
So, 'until' expression shall stop looping either if 'i' is greater than the length of the array, or if 'exit' is set to true.
If you finally opt to use 'Do until' please be careful with its limits.
Hope this helps