Global variables in matlab

I have a file_1.m file which has the following code;

global a;
a=1;
b=2;

file_2();

And my file_2.m has the following

function file_2

c=a+3;

d=2;

end

I had thought that since I have declared "a" as global in file_1.m, file_2 should have access to its value without passing a as an argument.

But it does not. How is it possible for file_2 to have access to the value of 'a' without passing it as an argument?

Answer 1

[Walter Roberson]

You need to specifically say that the variable is in the global namespace in the second file.

global a

Answer 2

[Image Analyst]

See the discussion of globals here in the FAQ. Basically it's more like friend than global , in that only functions that also declare the variable will be able to see it , and functions that don't declare the variable as global will not be able to see it.