Wait? Is what I 'm hearing correct? In C# (C hash tag), when you make a variable public within ...

[G+_James Coleman]

Wait? Is what I'm hearing correct? In C# (C hash tag), when you make a variable public within a class, it becomes a global variable that every function in every class can call without mentioning that object???

 

From what I remember, those variables are only available in side of that object, but because they are public, you can access it from the object by calling object.variable.

 

A global variable is where when you put the variable out side of the class and it is available to every function in every class.

[G+_Volkan Paksoy]

It doesn't become a global variable. It just becomes a member. If you don't explicitly specify scope it is declared as "private" by default that means you can only access it from inside that class only. 

[G+_James Coleman]

Volkan Paksoy Let's take this as an example.

 

https://github.com/GRMrGecko/GeckoReporter/blob/master/Classes/Framework/MGMReporter.h#L22

 

This is some code I wrote. Line 22-27 are global variables, and line 34-36 are object variables. The difference between global and object variables is that global is accessible from anywhere and object variables are only accessible to that object. In Obj-C, you can make a object variable accessible to other objects by declaring them as properties, but they do not become global like how I thought I heard in the podcast.

[G+_Nevrin O]

this might help

http://msdn.microsoft.com/en-us/library/ms173121.aspx

 

that link is for c#

From what i remember with java is that its slightly different but similar. so probably best not to assume its exactly the same between different languages.

[G+_Volkan Paksoy]

James Coleman I don't know Objective-C so I cannot comment on that. I think the easiest way would be to quickly create a test application with 2 classes in it. Create private and public variables inside one and try to access them via an instance of that class. You can play around with various modifiers by checking out the link Nevrin O  sent.

[G+_James Coleman]

Nevrin O how do you access the variable. Can you just access it as class.name or object.name or just name?

 

If you can access it by just name it's a global variable.

If you can access it by class.name, it's a object global variable (these don't exist in objective-c, except for methods with a + in front).

If you can access it by object.name, it's a object variable that is only accessible when you allocate the class as an object.

[G+_Volkan Paksoy]

To access a variable as class.variableName you have to define it as a "static" variable. 

 

http://msdn.microsoft.com/en-us/library/98f28cdx.aspx

[G+_James Coleman]

Volkan Paksoy So in other words they are assigned to the class and are not actually global variables. I never tried making a object static in an Objective-C class, would be interesting to see how it reacts. I know when you make a variable static in a function (if I remember correctly), it's only global to that function.

[G+_Volkan Paksoy]

James Coleman Static variables are shared among all instances of the class. They are not global. you were asking about accessing a variable as "class.name" that's why I mentioned it.