virtual method

Topic description  

Create a virtual method and a non-virtual method, then inherit from another class respectively, and compare the results of their invocations. (console application)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace virtual method
{
    class class1
    {
//The default method is designated as private and can only be accessed in the current class, the default is private
//If you need to access it in other classes, you need to specify it as public: the highest access rights, as long as you can access it within the project
//virtual keyword must be before void
        public virtual void virtualMethod()//Virtual methods can be overridden in derived classes
        {
            Console.WriteLine("This is a virtual method");
        }
        public void nonVirtualMethod()
        {
            Console.WriteLine("This is a non-virtual method");
        }
    }
    class class2 : class1//Inherit class2 with class1
    {
        public override void virtualMethod()
        {
            Console.WriteLine("This is a newly written virtual method");
        }
        public new void nonVirtualMethod()
        {
            Console.WriteLine("This is a new method");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            class1 c1 = new class1();//Instantiate the class
            c1.virtualMethod();
            c1.nonVirtualMethod();
            class2 c2 = new class2();
            c2.virtualMethod();
            c2.nonVirtualMethod();
            c1 = c2;
            c1.virtualMethod();
            c1.nonVirtualMethod();
            Console.ReadKey();
        }
    }
}

***The implementation of a non-virtual method is immutable: the implementation is the same whether the method is called on an instance of the class in which it is declared or an instance of a derived class. In contrast, the process of implementing a virtual method is called overriding the method.