Question about Global variables

Anon

Hello,
My question might sound a bit silly...its mostly because im a bit confused about the usage of global variables. I do not understand why is that in every function i have to include global variables on the top. I know there is a better way..just don't know what it is. I have a feeling that I can avoid having to include the globals on the top of every function, perhaps by declaring a class?? My c++ knowledge is out of date...please help. I will be more than happy to explain further if my question is confusing. Also I have some questions about session management.

Sincerely,
V

spacemax

As I know, there is no easyer way to use global Variables. this is, because one of the rules of structured programming disallow the usage of global variables.

Every function has a input and a output. those variables are passed by value if you don't change them and by reference if you change them. this helps other people to read your program.

If you use global variables, they have to be declared at the start of a function to show all the others (not that you are a bad boy) that those variables could be changed inside this function.

brandonschnell

global vars are evil. avoid whenever possible. any program that requires numerous global vars needs to be re-thought.

most likely you'll want to pass the vars in the function parameter list. organizing commonly used vars & methods into classes is another way.

just avoid using global vars.

Anon

Wow...looks like you guys have left me more confused than I started out as. I know in C++ there are two ways of passing vars, By reference and by value. Value passing creates a copy of the var and reference passes a pointer to the memory location where the var is stored. And as Dominik Nufer suggested in his response...global var are bad idea, I agree with him. I am designing a custom forum for a small community and after passing around most of the vars in the registration process and pulling the profile, updating the profile functions as global var I am starting to see weird activity. I think this is a good place to use a class implementation. Any suggestions?

I much appreciate your input!