What are static classes?

John Burns

Hi
done a lot of looking about and all the examples i find are too complex to grasp.
would one of you guys be good enough to try and explain a static class and some basic return types? i know viod acts like a sub, it doesnt return a value ... and i know that public string or public int will act as a function and return a value of the declared data type with its access modifier set to public, i know this from VB experience.

but im not too sure on static classes and members? ...just after a very basic explaination if poss,.

thanks in advance

11 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sam Hobbs15y ago
Accepted answer
Also search these forums for previous replies. I know I wrote something about two weeks ago, and it is my own material that I wrote for the thread. A short version of what I said is that static is necessary for functions such as Main that are called by Windows. An important concept is instances; instances of non-static classes are created by new but there is always just one instance of static members of classes.

The public in public string and public int does not refer to the return value; the public refers to the function and means that the function can be accessed from outside the class. If a function is not public then it can be called only from functions in the class.
Sam Hobbs15y ago
You don't understand. The web site owners expect us to remind people to check the checkbox. They also request that people use existing resources such as articles (especially those listed in Our Recommended Articles in the right side of windows such as this one) to attempt to find answers before requesting assistance. If you call that moaning then you need to expect that or don't use the forums.

You don't understand the unbelievable amount of time I voluntarily spend trying to help people such as you.

The point I am trying to make is that anything you can do to reduce the amount of our time that is required to help you is appreciated. When someone asks a question, then gets answers then decides to ask the same question again in a new thread without mentioning the previous assistance, it can waste time and most of the people that are willing to help you will not appreciate the waste of time.

So go ahead and reply to this, but I think I have said enough for now.
John Burns15y ago
you didnt understand what i was getting at, your answes dont really help Sam. im new, and i am considerate of the time on here, but yours just seems to be moaning at people all the time.
Sam Hobbs15y ago
It is a matter of being considerate of our time.
John Burns15y ago
that may be true Sam but im still learning so some of the stuff may well be crossed over or re-questioned, i dont have a tutor remember and just starting out, a little slack wouldnt go a miss.
Sam Hobbs15y ago
As it turns out, it appears that the previous thread that I was thinking of was also started by you, John Burns.
John Burns15y ago
Thanks for all the help; Sam, Subhendu and Mahesh.
I can now understand static classes, actually not that difficult once you get you're head round it; i always try to make things complex for myself, its a bad habbit.
Makes much more sence now after reading the Recommended Articles.
Mahesh Chand15y ago
You can also search this site. Also see Our Recommended Articles in the right side.
Subhendu De15y ago
That would be a good thing to do.

Thanks.....
John Burns15y ago
i just sat and read that artical of MSDN a while ago; but thanks for your reply.
i shall sit and try working out some examples and figure out how everything fits together
Subhendu De15y ago
Static classes and class members are used to create data and functions that can be accessed without creating an instance of the class. Static class members can be used to separate data and behavior that is independent of any object identity: the data and functions do not change regardless of what happens to the object. Static classes can be used when there is no data or behavior in the class that depends on object identity.
A class can be declared static, indicating that it contains only static members. It is not possible to create instances of a static class using the new keyword. Static classes are loaded automatically by the .NET Framework common language runtime (CLR) when the program or namespace containing the class is loaded.

Use a static class to contain methods that are not associated with a particular object. For example, it is a common requirement to create a set of methods that do not act on instance data and are not associated to a specific object in your code. You could use a static class to hold those methods.

The main features of a static class are:

      They only contain static members.

      They cannot be instantiated.

      They are sealed.

      They cannot contain Instance Constructors.

Creating a static class is therefore much the same as creating a class that contains only static members and a private constructor. A private constructor prevents the class from being instantiated.

The advantage of using a static class is that the compiler can check to make sure that no instance members are accidentally added. The compiler will guarantee that instances of this class cannot be created.

Static classes are sealed and therefore cannot be inherited. Static classes cannot contain a constructor, although it is still possible to declare a static constructor to assign initial values or set up some static state.

A static method, field, property, or event is callable on a class even when no instance of the class has been created. If any instances of the class are created, they cannot be used to access the static member. Only one copy of static fields and events exists, and static methods and properties can only access static fields and static events. Static members are often used to represent data or calculations that do not change in response to object state; for instance, a math library might contain static methods for calculating sine and cosine.

Static class members are declared using the static keyword before the return type of the member.