How does one track a change in global variable values and error out?

To explain the problem:

Assume a global variable 'X' which can take only a finite/known value;

say 10,20,30 or 40;

If another value is assigned to X anywhere in the workspace, the code needs to error out. Is there a way to do this globally from a main/top file, rather than inserting checks at each assignment.

Just a thought.

Thaks

Answer 1

[TAB]

% ========== You Main function===========
function YourMainFunct()

global x;

x = 10; % Just Initialization

% Your implementation
m=rand(2,2);

WriteX(m(1,1));

end

% ======= A small function to write x ========
function WriteX(x_val)
    global x;

      if(x_val==10 || x_val==20 || x_val==30 || x_val==0)
          x = x_val;
      else
          error('Undefined value assigned to x');
      end

end

You can use function WriteX to write the value of x from any workspace.

[Ponnu Prasad]

Thanks, Good simple approach