How do you make a variables from outside a function work in that function?

Answer 1

declaring a variable before main() will be accessed in main as well as in function which is called a "global variable" or "external variable".

*edit* a very good programming practice, which is also necessary with some compilers, is to declare the variable inside the function as well with the extern declaration before the type declaration.

for example if you had this inside a function:

int func(){

int x = 0;

x++;

return x;

}

that would be fine, but to declare it externally, you should include extern inside the function

int x = 0;

int func(){

extern x;

x++;

return x;

}

assuming that we declared the variable globally, which we did.