Java vs. C#

protected Modifier

Java
 
public class A
{
    protected int x;
    static void F(A a, B b) {
        a.x = 1;        // Ok
        b.x = 1;        // Ok
    }
}
public class B extends A
{
    static void F(A a, B b) {
        a.x = 1;        // Ok
        b.x = 1;        // Ok
    }
}

C#
 
public class A
{
    protected int x;
    static void F(A a, B b) {
        a.x = 1;        // Ok
        b.x = 1;        // Ok
    }
}
public class B: A
{
    static void F(A a, B b) {
        a.x = 1;   // Error, must access
                   // through instance of B
        b.x = 1;   // Ok
    }
}