Friday, 7 September 2018

Parent-Child class declaration and initialization

using System;

namespace CSharpDemo
{
    public class A
    {
        public void print()
        {
            Console.Write("A \n");            
        }

        // private method decalaration
        private void securePrint(){
            Console.Write("secure print A \n");
        }

        public void allowPublicAccessToSecurePrint(){
            this.securePrint();
        }
    }

    public class B : A
    {
        public void print()
        {
            Console.Write("B \n");
        }

        // base keyword will allow to access parent class's public methods
        public void printFromA(){
            base.print();
            //// parent's private methods are not accessible in child
            //// base.securePrint();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            A aa = new A();
            aa.print(); // -------------------------------------------- output: A
            //// private member not accessible
            //// aa.securePrint();
            aa.allowPublicAccessToSecurePrint(); //-------------------- output: secure print A

            A ab = new B();
            ab.print(); // -------------------------------------------- output: A
            ab.allowPublicAccessToSecurePrint(); //-------------------- output: secure print A

            //// below code will give you compile time error
            //// An explicit conversion exists (are you missing a cast?) 
            //// B ba = new A();
            //// ba.print();

            B bb = new B();
            bb.print(); // -------------------------------------------- output: B
            bb.printFromA(); // --------------------------------------- output: A
            bb.allowPublicAccessToSecurePrint(); //-------------------- output: secure print A
        }
    }
}

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Parent-Child class declaration and initialization

using System; namespace CSharpDemo {     public class A     {         public void print()         {             Console.Wr...