I'm confused with classes, unions and structures. I already read them in books but still I'm confused. Can anybody enlighten me?
I'm confused with classes, unions and structures. I already read them in books but still I'm confused. Can anybody enlighten me?
Flamers are worst than Newbies
In C++, struct == class except that stucts are public by default, while classes are private. They are basically a collection of dataypes mixed together.
The members of a union share the same memory, so if you set one of the members you modify the others too.
MagosX.com
Give a man a fish and you feed him for a day.
Teach a man to fish and you feed him for a lifetime.
Keep reading books and the web. It's difficult to explain this stuff in a few sentances.
UNION - I assume that unions are supposed to be used to make efficient use of memory. I've personally never seen unions used in a real program, only in books... I'm not saying that unions are never used... probably rarely used.
STRUCTURE - Magos is right, there is little difference between structures and classes in C++. However, typically structures do not have member functions. This is because in C, a structure cannot have member functions. (There are no classes or member functions in C.)
You can have a structure called Employee, and specific instances of that structure like Makoy and DougDbug. These structures can have variables like:
Makoy.Salary
DougDbug.Salary
Makoy.Title
Doug.Title
CLASS - In object oriented programming, a specific instance of a class is an object. Makoy & DougDbug are objects. You can have the same member variables like:
Makoy.Salary
Makoy.Title
In addition, you can have member functions like:
Makoy.IncreaseSalary()
You cannot have functions like that in non-object oriented programming languages such as C. In C, functions would have to be outside the structure. You would have to pass a pointer to the structure into your IncreaseSalary() function. You would not have encapsulation.
You can avoid structures, and always use classes if you wish.
