Let me see if I understand. You are using the function named menu.
It returns a variable. You call that menu. Then you use menu in a switch case.
Should MATLAB know which version of menu should be used? The function? The variable? Even if you could make this work, do you understand how difficult your code will be to ever debug? An then, suppose you try to run this code twice in a row? MATLAB will now see a VARIABLE named menu. When you then try to use the FUNCTION named menu, MATLAB will get really confused, and throw an error.
What are the odds your code will run correctly? I certainly won't be taking any bets on the matter.
