Question

I have the Parent Class :

class clsTestParent
    {
        protected int x;

        public void Foo()
        {
            x = 10;
        }

    }

I have the Derrived Class as below:

class clsDerivedTest : clsTestParent
    {

            x = 10;
            Foo();

    }

But this is not working as I am getting following two errors:

Invalid token ‘=’ in class, struct, or interface member declaration
Method must have a return type

But the above statements works fine when I try to use them with a method in derived class as below:

 class clsDerivedTest : clsTestParent
    {


        public void myTestMethod()
        {
            x = 10;
            Foo();
        }
}

Why the protected var or methods are only accessible by using derived class methods but not direcly in the class.

I even tried accessing the Protected member by creating object as below:

clsDerivedTest objDerivedTest = new clsDerivedTest();
            objDerivedTest.x = 10;

But again getting error for Protection Level. I have the var as protected so why the object of derived class can not access it?

I need to clear my fundamentals of OOPs but stuck here.

Answer 1

You know your problem –
I need to clear my fundamentals of OOPs but stuck here.

Clear the concept of protected member:

The protected keyword is a member access modifier. A protected member is accessible from within the class in which it is declared, and from within any class derived from the class that declared this member.

class A 
{
   protected int x = 123;
}

class B : A 
{
   void F() 
   {
      A a = new A();  
      B b = new B();  
      a.x = 10;   // Error
      b.x = 10;   // OK
   }
}

Also, it will be good if you go through C# language specification. It will make your understanding clear.