for loop inside while loop

I made for loop (with length n) to calculate something. After i look at the final result, i needed to rerun the for loop until condition A is reach (which could be done by while loop). How do i do that?

For example: I wanted to obtain count = 100 and already do this for loop. How do i add the while loop so that the for loop will rerun until count = 100? Is this possible? Or do i need to change the for loop into while loop? My code is much more complex than just counting even numbers, so i was looking a way if i can just add the while loop, not changing the whole loop using while.

a=randperm(100,20);
count = 0;
for i=1:length(a)
    if mod(a(i),2) == 0 % searching for even numbers
        count = count + 1;
    end
end

[Walter Roberson]

Do you want the for i loop to be exited as soon as the count of 100 is reached, or do you want the for i to conclude and only exit if 100 or more has been reached by the end of the iteration ?

Answer 1

[Walter Roberson]

count = 0;

iters = 0;
while count < 100
    iters = iters + 1;
    a = randperm(100,20);
    for i=1:length(a)
        if mod(a(i),2) == 0 % searching for even numbers
            count = count + 1;
        end
    end
end

fprintf('count became %d after iteration #%d\n', count, iters);

count became 107 after iteration #11