Steven Yong's Weblog

Monday, November 14. 2005

C# and Java

I’ve been thinking that if you’re familiar with Java, it won’t be difficult for you to write code in C# (or vice-versa). But now I realized that isn’t not going to be straight-forward:

class A {
  protected void eat() {}
}
public class B extends A {
  public static void test() {
    A a = new B();
    B b = new B();
    a.eat();
    b.eat();
  }
}

It’s absolutely legal in Java, but it doesn’t compile in C#:

class A {
  protected void Eat() { }
}
class B : A {
  public static void Test() {
    A a = new B();
    B b = new B();   
    a.Eat(); // Compile-time error: 
//Cannot access protected member 'A.Eat()' via a qualifier of type 'A'; 
         //the qualifier must be of type 'B' (or derived from it)
    b.Eat();
  }
}