C - Inheritance - polymorphism - virtual function member (lower)

Create a method , Then the parameter is our parent class Animal（ When you pass it in, you should pass it to the parent class , Otherwise, if the parent class is passed in later , When calling, the subclass has some features, and the parent class does not necessarily have ）

public static void Display(Animal animal)
{
    System.Console.WriteLine(animal.Name);
}

And then, when called ,dog and cat All are Animal Subclasses of ,new Two objects

dog peachas = new dog();
    cat egg = new cat();
    

When we call a method , You can pass in the subclass object

Because the subclass has all the functional features of the parent class , So parameters can be subclasses

Display(peachas);
Display(egg);

In the last article is Supplement of operators

One or two lines are equivalent to the abbreviation of the writing in the lower right corner

s This is a new variable , Give him a display conversion , This quoted s Variables can be used immediately

virtual

Marked as virual Functions of can be overridden by subclasses , Including method , Indexer , attribute , event       

public class Animal
{
    public string Name;
    public virtual decimal Liability => 0; 
}

Then the subclass should override the parent class with override Modifier  

  

public class Egg : Animal { public long sharesOwbed; }
public class ass : Animal
{
    public double mansion;
    public override decimal Liability => (decimal)mansion;
}

  Make a down conversion

ass mansion = new ass
{mansion = 2500 };
Animal a = mansion;
Console.WriteLine(mansion.Liability);
Console.WriteLine(a.Liability);

Both results are 2500