MATLAB: Matlab accessing global variable from another m file

global variableMATLAB

so let say I have two files fileA.m & fileB.m in fileA.m I have this code
function fileA() 
 global dataX; 
 dataX = 100; 
end
in fileB.m I want to use if to check the value this is what I have in fileB.m
function fileB() 
   if dataX == 100 
   fprintf('Value is %f \n' , dataX); 
   else 
   fprintf('Value is NOT %f \n' , dataX);
   end 
end
however I'm having problem every time I run fileB.m I get this error Undefined function or variable 'dataX'.
so how can I access global variable from another .m file .. I'm new to Matlab

Best Answer

Please do not use global variables!
However if you must, you have to declare them as globals in every workspace that uses them. They don’t just magickally appear!
function fileB() 
   global dataX
   if dataX == 100 
   fprintf('Value is %f \n' , dataX); 
   else 
   fprintf('Value is NOT %f \n' , dataX);
   end 
end
Related Question