MATLAB: “Return” and “continue” functions!

continuereturn

Hello MATLAB experts 🙂

I have not got the concept of "return" and "continue" functions in MATLAB. I went through the help but the examples were not so comprehensive for me. Please could you kindly explain them with a nice example per each?

Have a nice WE,

Mehdi

Best Answer

Continue example:

function VALUE = somefunction
while SOME_CONDITION
  DO_THIS;
  if SOME_OTHER_CONDITION
    continue;
  end
  DO_THAT
end
VALUE = SOMETHING;

If SOME_OTHER_CONDITION is true, then continue will essentially skip any remaining statements (i.e., DO_THIS will be executed, but DO_THAT will be skipped) in the loop and re-enter the loop provided SOME_CONDITION is still true. If SOME_OTHER_CONDITION is false, then continue will not be encountered and will execute both DO_THIS and DO_THAT for that loop iteration.

Return example:

function VALUE = somefunction
while SOME_CONDITION
  DO_THIS;
  if SOME_OTHER_CONDITION
    VALUE = SOMETHING;
    return;
  end
  DO_THAT
end
DO_SOMETHING_ELSE;

If SOME_OTHER_CONDITION is true, then return will not only skip any remaining statements (i.e., DO_THIS will be executed, but DO_THAT will be skipped) but it will also completely exit the loop. return will also exit the function (skipping DO_SOMETHING_ELSE) and return VALUE. If SOME_OTHER_CONDITION is false, then return will not be encountered and will execute both DO_THIS and DO_THAT for that loop iteration.

Related Solutions

MATLAB: Does indent in live scripts not obey indent setting

This issue is already brought to the notice of our developers. They will investigate the matter further."

MATLAB: Running two while loops

As a general form you can use something like

need_to_repeat_outer_loop = true;
while need_to_repeat_outer_loop
    %some code








    need_to_repeat_inner_loop = true;
    while need_to_repeat_inner_loop
        %some code
        if some inner condition
            need_to_repeat_inner_loop = false;
        end
    end
    %some code
    if some outer condition
        need_to_repeat_outer_loop = false;
    end
end

Hower, in practice most of the time you would instead write

while true
    %some code
    while true
        %some code
        if some inner condition
            break;   %out of inner loop

        end
    end
    %some code
    if some outer condition
        break;
    end
end

Sometimes you are inside the inner loop and need to signal that the outer loop is to be stopped. For that you can use

while true
    %some code
    while true
        stop_outer = false;
        %some code
        if some inner condition
            stop_outer = true;
            break;   %out of inner loop
        end
    end
    if stop_outer;
        break;
    end
    %some code
end

Best Answer

Related Solutions

MATLAB: Does indent in live scripts not obey indent setting

MATLAB: Running two while loops

Related Question