How do I use the for loop to replace elements in an array?

My array doesn't have any requirements.

Answer 1

[Voss]

array = randi(7,1,20);
disp(array);

     4     3     3     5     7     7     7     6     1     5     7     4     1     6     5     1     2     4     2     7

% use a for loop to replace all the 4's in array with 19's:
for ii = 1:numel(array)
    if array(ii) == 4
        array(ii) = 19;
    end
end
disp(array);

    19     3     3     5     7     7     7     6     1     5     7    19     1     6     5     1     2    19     2     7