Question

What is the point of a static method in a non-static class?

I have trouble understanding the underlying errors with the code below:

class myClass
{
    public void print(string mess)
    {
        Console.WriteLine(mess);
    }
}

class myOtherClass
{
    public static void print(string mess)
    {
        Console.WriteLine(mess);
    }
}

public static class Test
{
    public static void Main()
    {
        myClass mc = new myClass();
        mc.print("hello");

        myOtherClass moc = new myOtherClass();
        moc.print("vhhhat?"); 
       //This says I can't access static method in non static context, but am I not?

    }
}

I can't ever think of a reason why one would declare a static method in a non-static class, so why will .NET not throw an exception error.

Furthermore,

moc.print("vhhhat?");

This will say I can't access static method in non static context but Test and main are static, what is it referring to ?

 45  60361  45
1 Jan 1970

Solution

 31

A static class means that you cannot use it in a non-static context, meaning that you cannot have an object instantiation of that class and call the method. If you wanted to use your print method you would have to do:

myOtherClass.print("vhhhat?");

This is not static, as you created an instantiation of the class called moc:

myOtherClass moc = new myOtherClass();
2009-07-24

Solution

 25

First, the error:

moc.print("vhhhat?");

Is trying to call a static method on an instance of the class (i.e. a non-static context). To properly call print(), you would do

myOtherClass.print("vhhhat?");

For the first question, there are many reasons to have static methods in a non-static class. Basically, if there is an operation associated with the class, but not with any particular instance of the class, it should be a static method. For example, String.Format() (or any of the String static methods) should not operate on string instances, but they should be associated with the String class. Therefore they are static.

2009-07-24