Syed Ahmed Zaki

Abstract class in C#

Posted on September 10, 2017 | Leave a comment

//abstract class can contain abstract method but it is not mandatory

using System;


namespace Abstract
{

   public abstract class Customer
    {
        public void Print()
        {
            Console.WriteLine("Print");
        }
    }


    public class Program:Customer
    {
        //public override void Print()
        //{
        //    Console.WriteLine("Print Method");
        //}

        public static void Main(string[] args)
        {

            //Customer c = new Program();
            //c.Print();
            //Console.ReadKey();
        }
    }
}

//abstract class can contain abstract method but it is not mandatory

using System;

namespace Abstract

{

public abstract class Customer

{

public void Print()

{

Console.WriteLine("Print");

}

public class Program:Customer

{

//public override void Print()

//{

// Console.WriteLine("Print Method");

//}

public static void Main(string[] args)

{

//Customer c = new Program();

//c.Print();

//Console.ReadKey();

}

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Posted in .NET, C#

Polymorphism: Method Overloading and Method Overriding and Method Hiding

Posted on September 9, 2017 | Leave a comment

using System;
using Polymorphism;

namespace Polymorphism
{
    public static class CalCc
    {
        public static int add(int a, int b)
        {
            return a + b;
        }

        public static int add(int a, int b, int c)
        {
            return a + b + c;
        }


        public static float add(float a, float b)
        {
            return (a + b);
        }
    }
}
    

    class ProgramTest
    {
        static void Main(string[] args)
        {
        Console.WriteLine(CalCc.add(12,23));
        Console.WriteLine(CalCc.add(12,23,25));
            Console.WriteLine(CalCc.add(5.6f,7.8f));
            Console.ReadKey();
        }
    }

using System;

using Polymorphism;

namespace Polymorphism

{

public static class CalCc

{

public static int add(int a, int b)

{

return a + b;

}

public static int add(int a, int b, int c)

{

return a + b + c;

}

public static float add(float a, float b)

{

return (a + b);

}

class ProgramTest

{

static void Main(string[] args)

{

Console.WriteLine(CalCc.add(12,23));

Console.WriteLine(CalCc.add(12,23,25));

Console.WriteLine(CalCc.add(5.6f,7.8f));

Console.ReadKey();

}

using System;
using Polymorphism;

namespace Polymorphism
{
    public static class CalCc
    {
        public static int add(int a, int b)
        {
            return a + b;
        }

        public static int add(int a, int b, int c)
        {
            return a + b + c;
        }


        public static float add(float a, float b)
        {
            return (a + b);
        }
    }
}
    

    class ProgramTest
    {
        static void Main(string[] args)
        {
        Console.WriteLine(CalCc.add(12,23));
        Console.WriteLine(CalCc.add(12,23,25));
            Console.WriteLine(CalCc.add(5.6f,7.8f));
            Console.ReadKey();
        }
    }

using System;

using Polymorphism;

namespace Polymorphism

{

public static class CalCc

{

public static int add(int a, int b)

{

return a + b;

}

public static int add(int a, int b, int c)

{

return a + b + c;

}

public static float add(float a, float b)

{

return (a + b);

}

class ProgramTest

{

static void Main(string[] args)

{

Console.WriteLine(CalCc.add(12,23));

Console.WriteLine(CalCc.add(12,23,25));

Console.WriteLine(CalCc.add(5.6f,7.8f));

Console.ReadKey();

}

Method Overriding:

//override mane ektar opor arekta chore bosha
//mane ekta method er opor arekta method chore boshakei bole method overriding
//eta runtime ei hoy
//jei method tay override hoy setay override use korte hoy
//jei method tar opor override hoy seake virtual sombodhon korte hoy
//in this example we are overriding the eat method
using System;

namespace MethodOverride
{
    class Program
    {
        static void Main(string[] args)
        {
            Dog d=new Dog();
            d.eat();
            Console.ReadKey();
        }
    }

    public class Animal
    {
        public virtual void eat()
        {
            Console.WriteLine("Eating Food.");
        }
    }


    public class Dog : Animal
    {
        public override void eat()
        {
            Console.WriteLine("Eating bread");
        }
        
    }

}

//override mane ektar opor arekta chore bosha

//mane ekta method er opor arekta method chore boshakei bole method overriding

//eta runtime ei hoy

//jei method tay override hoy setay override use korte hoy

//jei method tar opor override hoy seake virtual sombodhon korte hoy

//in this example we are overriding the eat method

using System;

namespace MethodOverride

{

class Program

{

static void Main(string[] args)

{

Dog d=new Dog();

d.eat();

Console.ReadKey();

}

public class Animal

{

public virtual void eat()

{

Console.WriteLine("Eating Food.");

}

public class Dog : Animal

{

public override void eat()

{

Console.WriteLine("Eating bread");

}

another good exmple:

using System;

namespace MethodOverrideExample
{
    class Program
    {
        static void Main(string[] args)
        {
            Cars[] c = new Cars[2];
            c[0]=new newCars();
            c[1]=new oldCars();

            foreach (Cars key in c)
            {
                key.printInfo();
            }
            Console.ReadKey();

        }
    }
    
    class Cars
    {
        public virtual void printInfo()
        {
            Console.WriteLine("This is the base class");
        }
    }

    class newCars : Cars
    {
        public  override void printInfo()
        {
            Console.WriteLine("This is new cars class");
        }

    }

    class oldCars : Cars
    {

        public override void printInfo()
        {
            Console.WriteLine("This is the old cars");
        }
       
    }


}

using System;

namespace MethodOverrideExample

{

class Program

{

static void Main(string[] args)

{

Cars[] c = new Cars[2];

c[0]=new newCars();

c[1]=new oldCars();

foreach (Cars key in c)

{

key.printInfo();

}

Console.ReadKey();

}

class Cars

{

public virtual void printInfo()

{

Console.WriteLine("This is the base class");

}

class newCars : Cars

{

public override void printInfo()

{

Console.WriteLine("This is new cars class");

}

class oldCars : Cars

{

public override void printInfo()

{

Console.WriteLine("This is the old cars");

}

this video is good for learning overriding:

Method Hiding:

using System;


namespace Method_Hiding
{
    class FC
    {
        public virtual void Display()
        {
            Console.WriteLine("FC: Display");
        }
    }

    class SC : FC
    {
        public new void Display()
        {
            //base.Display();
            Console.WriteLine("SC: Display");
        }
    }

    class TC : SC
    {
        public new void Display()
        {
            //base.Display();
            Console.WriteLine("TC: Display");
        }
    }



    class Program
    {
        static void Main(string[] args)
        {
            SC p1=new SC();
            p1.Display();

            //((FC) p1).Display(); oobject casting

            FC p2=new FC();
            p2.Display();


            // SC pp = new FC(); it is not possible
            Console.ReadKey();

        }
    }
}

using System;

namespace Method_Hiding

{

class FC

{

public virtual void Display()

{

Console.WriteLine("FC: Display");

}

class SC : FC

{

public new void Display()

{

//base.Display();

Console.WriteLine("SC: Display");

}

class TC : SC

{

public new void Display()

{

//base.Display();

Console.WriteLine("TC: Display");

}

class Program

{

static void Main(string[] args)

{

SC p1=new SC();

p1.Display();

//((FC) p1).Display(); oobject casting

FC p2=new FC();

p2.Display();

// SC pp = new FC(); it is not possible

Console.ReadKey();

}

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Posted in .NET, C#, OO Analysis and Design, OOP

Aggregation in OOP

Posted on September 9, 2017 | Leave a comment

using System;

namespace Aggregation
{
    public class Address
    {
        public string addressLine, city, state;

        public Address(string addressLine, string city, string state)
        {
            this.addressLine = addressLine;
            this.city = city;
            this.state = state;
        }

    }

    public class Employee
    {
        public int id;
        public string name;
        public Address address; //employee Has-A address

        public Employee(int id,string name, Address address)
        {
            this.id = id;
            this.name = name;
            this.address = address;
        }

        public void Display()
        {
            Console.WriteLine(id+" "+name+" "+address.addressLine+" "+address.city+" "+address.state);
        }

    }

    class Program
    {
        static void Main(string[] args)
        {
            Address a1=new Address("G-13","Sec-3","Noida");
            Employee e1=new Employee(1,"Sonoo",a1);
            e1.Display();
            Console.ReadKey();
        }
    }
}

using System;

namespace Aggregation

{

public class Address

{

public string addressLine, city, state;

public Address(string addressLine, string city, string state)

{

this.addressLine = addressLine;

this.city = city;

this.state = state;

}

public class Employee

{

public int id;

public string name;

public Address address; //employee Has-A address

public Employee(int id,string name, Address address)

{

this.id = id;

this.name = name;

this.address = address;

}

public void Display()

{

Console.WriteLine(id+" "+name+" "+address.addressLine+" "+address.city+" "+address.state);

}

class Program

{

static void Main(string[] args)

{

Address a1=new Address("G-13","Sec-3","Noida");

Employee e1=new Employee(1,"Sonoo",a1);

e1.Display();

Console.ReadKey();

}

I will discuss more later.

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Posted in .NET, C#

Inheritance in C#

Posted on September 9, 2017 | Leave a comment

Single Level Inheitance: Inheriting Fields

using System;

namespace InheitanceCsharp
{
    public class Employee
    {
        public float salary = 40000;
 
    }

    public class Programmer : Employee
    {
        public float bonus = 10000;
    }
    
    class TestInheritance
    {
        public static void Main(string[] args)
        {
            Programmer p1=new Programmer();
            Console.WriteLine("Salary: "+p1.salary);
            Console.WriteLine("Bonus: "+p1.bonus);
            Console.ReadKey();
        }
    }
}

using System;

namespace InheitanceCsharp

{

public class Employee

{

public float salary = 40000;

}

public class Programmer : Employee

{

public float bonus = 10000;

}

class TestInheritance

{

public static void Main(string[] args)

{

Programmer p1=new Programmer();

Console.WriteLine("Salary: "+p1.salary);

Console.WriteLine("Bonus: "+p1.bonus);

Console.ReadKey();

}

Single Level Inheritance: Inheriting Methods

using System;

namespace InheritMethod
{
    public class Animal
    {
        public void eat()
        {
            Console.WriteLine("Eating...");
        }
    }

    public class Dog : Animal
    {
        public void bark()
        {
            Console.WriteLine("Barking...");
        }
    }

    class TestInheritance
    {
        public static void Main(string[] args)
        {
            Dog d1=new Dog();
            d1.bark();
            d1.eat();
            Console.ReadKey();
        }
    }
}

using System;

namespace InheritMethod

{

public class Animal

{

public void eat()

{

Console.WriteLine("Eating...");

}

public class Dog : Animal

{

public void bark()

{

Console.WriteLine("Barking...");

}

class TestInheritance

{

public static void Main(string[] args)

{

Dog d1=new Dog();

d1.bark();

d1.eat();

Console.ReadKey();

}

Multilevel Inheritance:

//multiple inheritance is not supported in c# through class
//so it supports naturally multi level inheritance
//but we can use multiple inheritance using interface

using System;

namespace MultiLevelInheitance
{
    public class Animal
    {
        public void eat()
        {
            Console.WriteLine("Eating..");
        }

    }

    public class Dog : Animal
    {
        public void bark()
        {
            Console.WriteLine("Barking.....");
        }
    }

    public class BabyDog : Dog
    {
        public void weep()
        {
            Console.WriteLine("Weeping...");
        }
    }

    public class BabyBabyDog : BabyDog
    {
        public void Cry()
        {
            Console.WriteLine("Crying...");
        }
    }



    class TestInhertance
    {
        static void Main(string[] args)
        {
            BabyBabyDog bb=new BabyBabyDog();
            bb.eat();
            bb.bark();
            bb.weep();
            bb.Cry();
            Console.ReadLine();

        }
    }
}

//multiple inheritance is not supported in c# through class

//so it supports naturally multi level inheritance

//but we can use multiple inheritance using interface

using System;

namespace MultiLevelInheitance

{

public class Animal

{

public void eat()

{

Console.WriteLine("Eating..");

}

public class Dog : Animal

{

public void bark()

{

Console.WriteLine("Barking.....");

}

public class BabyDog : Dog

{

public void weep()

{

Console.WriteLine("Weeping...");

}

public class BabyBabyDog : BabyDog

{

public void Cry()

{

Console.WriteLine("Crying...");

}

class TestInhertance

{

static void Main(string[] args)

{

BabyBabyDog bb=new BabyBabyDog();

bb.eat();

bb.bark();

bb.weep();

bb.Cry();

Console.ReadLine();

}

Multiple Inheritance Through Interface:

//interface is just like class here

using System;

namespace MultipleInheritanceInterface
{
  
        interface calc1
        {
            int add(int a, int b);
        }

        interface calc2
        {
            int sub(int x, int y);
        }

        interface calc3
        {
            int mul(int r, int s);
        }

        interface calc4
        {
            int div(int c,int d);
        }

    class calculation : calc1, calc2, calc3, calc4
    {
        public int result1;

        public int add(int a, int b)
        {
            return result1 = a + b;
        }

        public int result2;

        public int sub(int x, int y)
        {
            return result2 = x - y;
        }

        public int result3;

        public int mul(int r,int s)
        {
            return result3 = r * s;
        }


        public int result4;
        public int div(int c, int d)
        {
            return result4 = c / d;
        }

    }

    class Program
    {

        static void Main(string[] args)
        {
            calculation c=new calculation();
            c.add(8, 2);
            c.sub(20, 10);
            c.mul(5,2);
            c.div(20, 10);

            Console.WriteLine("Multiple ineritance concept using interface:\n");

            Console.WriteLine("Addition:"+c.result1);
            Console.WriteLine("Substraction:"+c.result2);
            Console.WriteLine("Multiplication:"+c.result3);
            Console.WriteLine("Division:"+c.result4);
            Console.ReadKey();
        }
    }
}

//interface is just like class here

using System;

namespace MultipleInheritanceInterface

{

interface calc1

{

int add(int a, int b);

}

interface calc2

{

int sub(int x, int y);

}

interface calc3

{

int mul(int r, int s);

}

interface calc4

{

int div(int c,int d);

}

class calculation : calc1, calc2, calc3, calc4

{

public int result1;

public int add(int a, int b)

{

return result1 = a + b;

}

public int result2;

public int sub(int x, int y)

{

return result2 = x - y;

}

public int result3;

public int mul(int r,int s)

{

return result3 = r * s;

}

public int result4;

public int div(int c, int d)

{

return result4 = c / d;

}

class Program

{

static void Main(string[] args)

{

calculation c=new calculation();

c.add(8, 2);

c.sub(20, 10);

c.mul(5,2);

c.div(20, 10);

Console.WriteLine("Multiple ineritance concept using interface:\n");

Console.WriteLine("Addition:"+c.result1);

Console.WriteLine("Substraction:"+c.result2);

Console.WriteLine("Multiplication:"+c.result3);

Console.WriteLine("Division:"+c.result4);

Console.ReadKey();

}

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Posted in .NET, C#

Encapsulation in C#

Posted on September 9, 2017 | Leave a comment

using System;

namespace EncapsulationExample
{
    class Student
    {
        public string ID
        {
            get; set;
        }

        public string Name
        {
            get; set;
        }

        public string Email
        {
            get; set;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            //setting values to properties
            Student student1 = new Student();
            student1.ID = "101";
            student1.Name = "Zaki Live";
            student1.Email = "s@d.com";
            Student student2=new Student();

            student2.ID = "233";
            student2.Name = "SS";
            student2.Email = "S@p.com";

            //getting values to properties

            Console.WriteLine("ID="+student1.ID);
            Console.WriteLine("Name="+student1.Name);
            Console.WriteLine("Email="+student1.Email);

            Console.WriteLine("ID=" + student2.ID);
            Console.WriteLine("Name=" + student2.Name);
            Console.WriteLine("Email=" + student2.Email);

            Console.ReadKey();
        }
    }
}

using System;

namespace EncapsulationExample

{

class Student

{

public string ID

{

get; set;

}

public string Name

{

get; set;

}

public string Email

{

get; set;

}

class Program

{

static void Main(string[] args)

{

//setting values to properties

Student student1 = new Student();

student1.ID = "101";

student1.Name = "Zaki Live";

student1.Email = "[email protected]";

Student student2=new Student();

student2.ID = "233";

student2.Name = "SS";

student2.Email = "[email protected]";

//getting values to properties

Console.WriteLine("ID="+student1.ID);

Console.WriteLine("Name="+student1.Name);

Console.WriteLine("Email="+student1.Email);

Console.WriteLine("ID=" + student2.ID);

Console.WriteLine("Name=" + student2.Name);

Console.WriteLine("Email=" + student2.Email);

Console.ReadKey();

}

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Posted in .NET, C#

C# Access Modifiers/Specifiers

Posted on September 8, 2017 | Leave a comment

C# Provides five types of access specifiers:

They are: Public, Private, Protected, Internal, Protected Internal

Public – It specifies that access is not restricted
Protected- It specifies that access is limited to the containing class or in a derived class
Internal – It specifies that access is limited to the current assembly
Protected Internal – It specifes that access is limited to the current asembly or types from the derived class
Private – It specifies that acess is limited to the containing type

this video will surely help to understand:

Now lets see the example:
public:

using System;

namespace Public
{
    class Program
    {
        public string name = "Shantosh Kumar";

        public void Msge(string msg)
        {
            Console.WriteLine("Hello "+msg);
        } 
    }

    class TestingPublic
    {

        static void Main(string[] args)
        {
            Program p1=new Program();
            Console.WriteLine("Hello "+p1.name);
            p1.Msge("Live");
            Console.ReadKey();
        }
    }
}

using System;

namespace Public

{

class Program

{

public string name = "Shantosh Kumar";

public void Msge(string msg)

{

Console.WriteLine("Hello "+msg);

}

class TestingPublic

{

static void Main(string[] args)

{

Program p1=new Program();

Console.WriteLine("Hello "+p1.name);

p1.Msge("Live");

Console.ReadKey();

}

protected:

using System;


namespace Protected
{
    class ProtectedTest
    {
        protected string name = "Syed Ahmed Zaki";
        protected void msg(string msg)
        {
            Console.WriteLine("Hello "+msg);
        }
    }
    class Program
    {
        ProtectedTest p1=new ProtectedTest();
        static void Main(string[] args)
        {
            Console.WriteLine("Hello: "+p1.name);
            ProtectedTest.msg("Rahim");
        }
    }
}

using System;

namespace Protected

{

class ProtectedTest

{

protected string name = "Syed Ahmed Zaki";

protected void msg(string msg)

{

Console.WriteLine("Hello "+msg);

}

class Program

{

ProtectedTest p1=new ProtectedTest();

static void Main(string[] args)

{

Console.WriteLine("Hello: "+p1.name);

ProtectedTest.msg("Rahim");

}

output: it will show error

but we can show the output through some tricks

//we are inheriting here the protected class
using System;


namespace Protected
{
    class ProtectedTest
    {
        protected string name = "Syed Ahmed Zaki";
        protected void msg(string msg)
        {
            Console.WriteLine("Hello "+msg);
        }
    }
    class Program:ProtectedTest
    {
        //ProtectedTest p1=new ProtectedTest();
       
        static void Main(string[] args)
        {
            Program pp = new Program();
            Console.WriteLine("Hello "+pp.name);
            pp.msg("Rahim");
            Console.ReadKey();
        }
    }
}

//we are inheriting here the protected class

using System;

namespace Protected

{

class ProtectedTest

{

protected string name = "Syed Ahmed Zaki";

protected void msg(string msg)

{

Console.WriteLine("Hello "+msg);

}

class Program:ProtectedTest

{

//ProtectedTest p1=new ProtectedTest();

static void Main(string[] args)

{

Program pp = new Program();

Console.WriteLine("Hello "+pp.name);

pp.msg("Rahim");

Console.ReadKey();

}

output:

Hello Syed Ahmed Zaki
Hello Rahim

1 2	Hello Syed Ahmed Zaki Hello Rahim

Internal:

using System;

namespace InternalTest
{
   static class InternalTestaaa
    {
        internal static string name = "Zaki Live";

        internal static void msg(string msg)
        {
            Console.WriteLine("Hello: "+msg);
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello "+InternalTestaaa.name);
            InternalTestaaa.msg("Chiki Tita");
            Console.ReadKey();
        }
    }
}

using System;

namespace InternalTest

{

static class InternalTestaaa

{

internal static string name = "Zaki Live";

internal static void msg(string msg)

{

Console.WriteLine("Hello: "+msg);

}

class Program

{

static void Main(string[] args)

{

Console.WriteLine("Hello "+InternalTestaaa.name);

InternalTestaaa.msg("Chiki Tita");

Console.ReadKey();

}

Protected Internal:

private:

eg 1:

//different class it is showing error while private

using System;

namespace Private
{
    class PrivateTest
    {
        private string name = "Shantosh Kumar";

        private void Msg(string msg)
        {
            Console.WriteLine("Hello"+msg);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            PrivateTest pvt1=new PrivateTest();
            //Accessing private variable
            Console.WriteLine("Hello "+pvt1.name);
            //accessing private function
            pvt1.Msg();
            Console.ReadKey();
        }
    }

}

//different class it is showing error while private

using System;

namespace Private

{

class PrivateTest

{

private string name = "Shantosh Kumar";

private void Msg(string msg)

{

Console.WriteLine("Hello"+msg);

}

class Program

{

static void Main(string[] args)

{

PrivateTest pvt1=new PrivateTest();

//Accessing private variable

Console.WriteLine("Hello "+pvt1.name);

//accessing private function

pvt1.Msg();

Console.ReadKey();

}

eg 2:

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Posted in .NET, C#

C# Structs works almost like a Class !

Posted on September 8, 2017 | Leave a comment

//it is also working like as class
//its one time definable
using System;


namespace CStructs
{
    public struct Rectangle
    {
        public int height, width;
    }



    class TestStructs
    {
        static void Main(string[] args)
        {
            Rectangle r=new Rectangle();
            r.height = 4;
            r.width = 5;
            Console.WriteLine("Area of rectangle is:"+(r.height*r.width));

        }
    }
}

//it is also working like as class

//its one time definable

using System;

namespace CStructs

{

public struct Rectangle

{

public int height, width;

}

class TestStructs

{

static void Main(string[] args)

{

Rectangle r=new Rectangle();

r.height = 4;

r.width = 5;

Console.WriteLine("Area of rectangle is:"+(r.height*r.width));

}

//constrcutor and method is also possible with structs 
//struct does not suppost inheritance but it can implement intrfaces
using System;

namespace StructConstructor
{
    public struct Rectangle
    {
        public int width, height;

        public Rectangle(int w,int h)
        {
            width = w;
            height = h;
        }

        public void AreaOfRectangle()
        {
            Console.WriteLine("Area of rectangle:"+(width*height));
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Rectangle r=new Rectangle(5,6);
            r.AreaOfRectangle();
            Console.ReadKey();
        }
    }
}

//constrcutor and method is also possible with structs

//struct does not suppost inheritance but it can implement intrfaces

using System;

namespace StructConstructor

{

public struct Rectangle

{

public int width, height;

public Rectangle(int w,int h)

{

width = w;

height = h;

}

public void AreaOfRectangle()

{

Console.WriteLine("Area of rectangle:"+(width*height));

}

class Program

{

static void Main(string[] args)

{

Rectangle r=new Rectangle(5,6);

r.AreaOfRectangle();

Console.ReadKey();

}

Leave a comment

Posted in .NET, C#

How many constructor a class have in C# ?

Posted on September 7, 2017 | Leave a comment

Is it known as constructor overloading ?

//we can also print it from constructor
using System;


namespace ConstructorOverloading
{
    class GameScore
    {
         string user;
         int age;
         int salary;

        public GameScore() //it is default constructor
        {
            user = "Steven";
            age = 28;
            Console.WriteLine("Previous user: "+user+" and he was "+age+" year old");
        }

        public GameScore(string name,int age)
        {
            user = name;
            this.age = age;
            Console.WriteLine("Current user {0} and he is {1} years old",user,this.age);
        }

        public GameScore(int age, int salary)
        {
            this.age = age;
            this.salary = salary;
            Console.WriteLine("From the third constructor Age="+age+" Salary:"+salary);
        }

        public void Display(int no)
        {
            Console.WriteLine("Output from "+no+" no. Constructor");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            GameScore g1=new GameScore();
            GameScore g2=new GameScore("Zaki",25);
            GameScore g3=new GameScore(90,99);
            g3.Display(3);
            Console.ReadKey();
        }
    }
}

//we can also print it from constructor

using System;

namespace ConstructorOverloading

{

class GameScore

{

string user;

int age;

int salary;

public GameScore() //it is default constructor

{

user = "Steven";

age = 28;

Console.WriteLine("Previous user: "+user+" and he was "+age+" year old");

}

public GameScore(string name,int age)

{

user = name;

this.age = age;

Console.WriteLine("Current user {0} and he is {1} years old",user,this.age);

}

public GameScore(int age, int salary)

{

this.age = age;

this.salary = salary;

Console.WriteLine("From the third constructor Age="+age+" Salary:"+salary);

}

public void Display(int no)

{

Console.WriteLine("Output from "+no+" no. Constructor");

}

class Program

{

static void Main(string[] args)

{

GameScore g1=new GameScore();

GameScore g2=new GameScore("Zaki",25);

GameScore g3=new GameScore(90,99);

g3.Display(3);

Console.ReadKey();

}

Leave a comment

Posted in .NET, C#

Tagged C sharp, contrcutor, overloading

C# usage of Static Keyword

Posted on September 7, 2017 | Leave a comment

//static field
using System;

namespace StaticKeyword
{
    public class Account
    {
        public int accno;
        public string name;
        public static float rateOfInterest = 8.8f;

        public Account(int accno,string name)
        {
            this.accno = accno;
            this.name = name;
        }

        public void display()
        {
            Console.WriteLine(accno+" "+name+" "+rateOfInterest);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {

            Account a1=new Account(101,"Soonoo");
            Account a2=new Account(102, "Mahesh");
            a1.display();
            a2.display();
            Console.ReadKey();
        }
    }
}

//static field

using System;

namespace StaticKeyword

{

public class Account

{

public int accno;

public string name;

public static float rateOfInterest = 8.8f;

public Account(int accno,string name)

{

this.accno = accno;

this.name = name;

}

public void display()

{

Console.WriteLine(accno+" "+name+" "+rateOfInterest);

}

class Program

{

static void Main(string[] args)

{

Account a1=new Account(101,"Soonoo");

Account a2=new Account(102, "Mahesh");

a1.display();

a2.display();

Console.ReadKey();

}

//changing static field
using System;

namespace StaticKeyword
{

    public class Account
    {
        public int accno;
        public string name;
        public static float rateOfInterest = 8.8f;

        public Account(int accno,string name)
        {
            this.accno = accno;
            this.name = name;
        }

        public void display()
        {
            Console.WriteLine(accno+" "+name+" "+rateOfInterest);
        }

    }

    class Program
    {
        static void Main(string[] args)
        {

            Account.rateOfInterest = 55.65f; //we are changing the value of this variable by calling from main method
            Account a1=new Account(101,"Soonoo");
            Account a2=new Account(102, "Mahesh");
            a1.display();
            a2.display();
            Console.ReadKey();
        }
    }
}

//changing static field

using System;

namespace StaticKeyword

{

public class Account

{

public int accno;

public string name;

public static float rateOfInterest = 8.8f;

public Account(int accno,string name)

{

this.accno = accno;

this.name = name;

}

public void display()

{

Console.WriteLine(accno+" "+name+" "+rateOfInterest);

}

class Program

{

static void Main(string[] args)

{

Account.rateOfInterest = 55.65f; //we are changing the value of this variable by calling from main method

Account a1=new Account(101,"Soonoo");

Account a2=new Account(102, "Mahesh");

a1.display();

a2.display();

Console.ReadKey();

}

//changing static field when calling from another field
//without static declaring it is not possible
using System;

namespace StaticKeyword
{

    public class Account
    {
        public int accno;
        public string name;
        public static int count = 0;
        public static float rateOfInterest = 8.8f;

        public Account(int accno,string name)
        {
            this.accno = accno;
            this.name = name;
            count++;
        }

        public void display()
        {
            Console.WriteLine(accno+" "+name+" "+rateOfInterest);
        }

    }

    class Program
    {
        static void Main(string[] args)
        {

            Account.rateOfInterest = 55.65f; //we are changing the value of this variable by calling from main method
            Account a1=new Account(101,"Soonoo");
            Account a2=new Account(102, "Mahesh");
            Account a3 = new Account(102, "Jatra");
            Account a4 = new Account(102, "Jatra pala");
            a1.display();
            a2.display();
            a3.display();
            Console.WriteLine("Total object count here:"+Account.count);
            Console.ReadKey();
        }
    }
}

//changing static field when calling from another field

//without static declaring it is not possible

using System;

namespace StaticKeyword

{

public class Account

{

public int accno;

public string name;

public static int count = 0;

public static float rateOfInterest = 8.8f;

public Account(int accno,string name)

{

this.accno = accno;

this.name = name;

count++;

}

public void display()

{

Console.WriteLine(accno+" "+name+" "+rateOfInterest);

}

class Program

{

static void Main(string[] args)

{

Account.rateOfInterest = 55.65f; //we are changing the value of this variable by calling from main method

Account a1=new Account(101,"Soonoo");

Account a2=new Account(102, "Mahesh");

Account a3 = new Account(102, "Jatra");

Account a4 = new Account(102, "Jatra pala");

a1.display();

a2.display();

a3.display();

Console.WriteLine("Total object count here:"+Account.count);

Console.ReadKey();

}

Static Class Example:

//using static class
//we need object reference where it is clearing up
//it is sealed and cannot be called/instantiated

using System;

namespace StaticKeyword
{
    public static class MyMath
    {

        public static float pi = 3.14f;

        public static int cube(int n)
        {
            return n * n * n;
        }
    }


    class TestMath
    {
        public static void Main(string[] args)
        {
            
            Console.WriteLine("Value of PI is:"+MyMath.pi);
            Console.WriteLine("Cube of 3 is:"+MyMath.cube(3));
            Console.ReadKey();
        }
        
    }
}

//using static class

//we need object reference where it is clearing up

//it is sealed and cannot be called/instantiated

using System;

namespace StaticKeyword

{

public static class MyMath

{

public static float pi = 3.14f;

public static int cube(int n)

{

return n * n * n;

}

class TestMath

{

public static void Main(string[] args)

{

Console.WriteLine("Value of PI is:"+MyMath.pi);

Console.WriteLine("Cube of 3 is:"+MyMath.cube(3));

Console.ReadKey();

}

Static Constructor:

using System;


public class Account
{
    public int id;
    public string name;
    public static float rateOfInterest;

    public Account(int id, string name)
    {
        this.id = id;
        this.name = name;
    }

    static Account()
    {
        rateOfInterest = 9.5f;
    }

    public void display()
    {
        Console.WriteLine(id+" "+name+" "+rateOfInterest );
    }

}

class TestEmployee
{
    public static void Main(string[] args)
    {
        Account a1=new Account(101,"dss");
        Account a2=new Account(202,"dssd");
        a1.display();
        a2.display();
        Console.ReadKey();
    }
}

using System;

public class Account

{

public int id;

public string name;

public static float rateOfInterest;

public Account(int id, string name)

{

this.id = id;

this.name = name;

}

static Account()

{

rateOfInterest = 9.5f;

}

public void display()

{

Console.WriteLine(id+" "+name+" "+rateOfInterest );

}

class TestEmployee

{

public static void Main(string[] args)

{

Account a1=new Account(101,"dss");

Account a2=new Account(202,"dssd");

a1.display();

a2.display();

Console.ReadKey();

}

Leave a comment

Posted in .NET, C#

Tagged static

C# Constructor and Destructor

Posted on September 6, 2017 | Leave a comment

//default constructor example
//When a method name is same as class name we call it as constructor
//a constructor which has no argument is known as default constructor
using System;

namespace ConstructorCreation
{
    public class Employee
    {
        public Employee()
        {
            Console.WriteLine("Default Constructor Invoked Hoyeche");
        }

 
    }

    class Program
    {
        static void Main(string[] args)
        {
            Employee e1=new Employee();
            Employee e2=new Employee(); //we are creating object here
            Console.ReadKey();
        }
    }
}

//default constructor example

//When a method name is same as class name we call it as constructor

//a constructor which has no argument is known as default constructor

using System;

namespace ConstructorCreation

{

public class Employee

{

public Employee()

{

Console.WriteLine("Default Constructor Invoked Hoyeche");

}

class Program

{

static void Main(string[] args)

{

Employee e1=new Employee();

Employee e2=new Employee(); //we are creating object here

Console.ReadKey();

}

//default constructor example
//When a method name is same as class name we call it as constructor
//a constructor which has no argument is known as default constructor
//main in same class
using System;

namespace ConstructorCreation
{
    public class Employee
    {
        public Employee()
        {
            Console.WriteLine("Default Constructor Invoked Hoyeche");
        }
  
        static void Main(string[] args)
        {
            Employee e1=new Employee();
            Employee e2=new Employee(); //we are creating object here
            Console.ReadKey();
        }
    }
}

//default constructor example

//When a method name is same as class name we call it as constructor

//a constructor which has no argument is known as default constructor

//main in same class

using System;

namespace ConstructorCreation

{

public class Employee

{

public Employee()

{

Console.WriteLine("Default Constructor Invoked Hoyeche");

}

static void Main(string[] args)

{

Employee e1=new Employee();

Employee e2=new Employee(); //we are creating object here

Console.ReadKey();

}

//parameterized constructor
//constructors is one kind of method where method name and class name is same
using System;

namespace ParameterizedConstructor
{
    public class Employee
    {
        public int id;
        public string name;
        public float salary;

        public Employee(int i, string n, float s)
        {
            id = i;
            name = n;
            salary = s;
        }

        public void Display()
        {
            Console.WriteLine(id+" "+name+" "+salary);
        }

    }

class TestEmployee
    {

        static void Main(string[] args)
        {
         Employee e1 = new Employee(101, "Zaki", 555.56f);
         Employee e2 = new Employee(624, "Live", 6666.5f);
          e1.Display();
          e2.Display();

          Console.ReadKey();
        }
    }
}

//parameterized constructor

//constructors is one kind of method where method name and class name is same

using System;

namespace ParameterizedConstructor

{

public class Employee

{

public int id;

public string name;

public float salary;

public Employee(int i, string n, float s)

{

id = i;

name = n;

salary = s;

}

public void Display()

{

Console.WriteLine(id+" "+name+" "+salary);

}

class TestEmployee

{

static void Main(string[] args)

{

Employee e1 = new Employee(101, "Zaki", 555.56f);

Employee e2 = new Employee(624, "Live", 6666.5f);

e1.Display();

e2.Display();

Console.ReadKey();

}

Destructor:

//destructor is known as finalizer in c#
//destructor can't be public 
//destructor does not contain any modifiers
using System;


namespace Destructor
{

    class Employee
    {


        public Employee()
        {
            Console.WriteLine("Constructor Invoked");
        }

        ~Employee()
        {
            Console.WriteLine("Destructor Invoked");
        }

    }


    class TestEmployee
    {
        static void Main(string[] args)
        {
            Employee e1=new Employee();
            Employee e2=new Employee();

            Console.ReadKey();

        }
    }
}

//destructor is known as finalizer in c#

//destructor can't be public

//destructor does not contain any modifiers

using System;

namespace Destructor

{

class Employee

{

public Employee()

{

Console.WriteLine("Constructor Invoked");

}

~Employee()

{

Console.WriteLine("Destructor Invoked");

}

class TestEmployee

{

static void Main(string[] args)

{

Employee e1=new Employee();

Employee e2=new Employee();

Console.ReadKey();

}

Leave a comment

Posted in .NET, C#

Tagged C++, Constructor, OOP

C# Object and Classes

Posted on September 5, 2017 | Leave a comment

//having main in another class
using System;

namespace OObj1
{
    class Student1
    {
        public int id;
        public string name;
        
    }

    class TestStudent
    {
        public static void Main(String[] args)
        {
            Student1 s1=new Student1();
            s1.id = 200;
            s1.name = "Dhaa";
            Console.WriteLine(s1.id);
            Console.WriteLine(s1.name);
            Console.ReadKey();
        }
    }


}

//having main in another class

using System;

namespace OObj1

{

class Student1

{

public int id;

public string name;

}

class TestStudent

{

public static void Main(String[] args)

{

Student1 s1=new Student1();

s1.id = 200;

s1.name = "Dhaa";

Console.WriteLine(s1.id);

Console.WriteLine(s1.name);

Console.ReadKey();

}

//having main in same class
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace OObj1
{
    class Student
    {
        int id;
        String name;
        static void Main(string[] args)
        {
            Student s1=new Student();// creating an object of student
            s1.id = 101;
            s1.name = "Zaki";
            Console.WriteLine(s1.id);
            Console.WriteLine(s1.name);
            Console.ReadKey();
        }
    }
}

//having main in same class

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace OObj1

{

class Student

{

int id;

String name;

static void Main(string[] args)

{

Student s1=new Student();// creating an object of student

s1.id = 101;

s1.name = "Zaki";

Console.WriteLine(s1.id);

Console.WriteLine(s1.name);

Console.ReadKey();

}

//initialize and display data through method
using System;

namespace OOMethod
{
    class Student
    {
        public int id;
        public String name;

        public void insertOOP(int i, String n)
        {
            id = i;
            name = n;
        }

        public void display()
        {
            Console.WriteLine(id + " " + name);
        }

    }

    class Printing { 
    static void Main(string[] args)
        {
            Student s1=new Student();
            Student s2=new Student();
            s1.insertOOP(101,"Zaki");
            s2.insertOOP(209,"Live");
            s1.display();
            s2.display();
            Console.ReadKey();
        }
    }
}

//initialize and display data through method

using System;

namespace OOMethod

{

class Student

{

public int id;

public String name;

public void insertOOP(int i, String n)

{

id = i;

name = n;

}

public void display()

{

Console.WriteLine(id + " " + name);

}

class Printing {

static void Main(string[] args)

{

Student s1=new Student();

Student s2=new Student();

s1.insertOOP(101,"Zaki");

s2.insertOOP(209,"Live");

s1.display();

s2.display();

Console.ReadKey();

}

//store and display employee information using method
using System;

namespace OOMethod
{
    class Employee
    {
        public int id;
        public string name;
        public float salary;

        public void insert(int i,string n,float s)
        {
            id = i;
            name = n;
            salary = s;
        }

        public void display()
        {
            Console.WriteLine(id+" "+name+" "+salary);
        }
    }

    class TestEmployee
    {
        public static void Main(String[] args)
        {
            Employee e1=new Employee();
            Employee e2=new Employee();
            e1.insert(101,"Zaki",9898f);
            e2.insert(202,"Live",999f);
            e1.display();
            e2.display();
            Console.ReadKey();
        }
    }
}

//store and display employee information using method

using System;

namespace OOMethod

{

class Employee

{

public int id;

public string name;

public float salary;

public void insert(int i,string n,float s)

{

id = i;

name = n;

salary = s;

}

public void display()

{

Console.WriteLine(id+" "+name+" "+salary);

}

class TestEmployee

{

public static void Main(String[] args)

{

Employee e1=new Employee();

Employee e2=new Employee();

e1.insert(101,"Zaki",9898f);

e2.insert(202,"Live",999f);

e1.display();

e2.display();

Console.ReadKey();

}

//"this" keyword it is used if field names(instance variable) and parameters names are same in a method, that is why both can be distinguish easily

using System;

namespace UsingThis
{

    public class Employee
    {
        public int id;
        public string name;
        public float salary;


        public Employee(int id,string name, float salary)
        {
            this.id = id;
            this.name = name;
            this.salary = salary;
        }

        public void Display()
        { 
            Console.WriteLine(id+" "+name+" "+salary);
        }

    }

    class Program
    {
        static void Main(string[] args)
        {
            Employee e1=new Employee(101,"Zaki",101.55f);
            Employee e2=new Employee(2015,"Live",665.55f);
            e1.Display();
            e2.Display();
            Console.ReadKey();
        }
    }
}

//"this" keyword it is used if field names(instance variable) and parameters names are same in a method, that is why both can be distinguish easily

using System;

namespace UsingThis

{

public class Employee

{

public int id;

public string name;

public float salary;

public Employee(int id,string name, float salary)

{

this.id = id;

this.name = name;

this.salary = salary;

}

public void Display()

{

Console.WriteLine(id+" "+name+" "+salary);

}

class Program

{

static void Main(string[] args)

{

Employee e1=new Employee(101,"Zaki",101.55f);

Employee e2=new Employee(2015,"Live",665.55f);

e1.Display();

e2.Display();

Console.ReadKey();

}

Leave a comment

Posted in .NET, C#

Tagged C++, class, object, OOP

Story, Motivation about Life!

Posted on August 28, 2017 | Leave a comment

#Collected From a Facebook Post

Leave a comment

Posted in Motivation, Motivational Posts

Tagged Life Lessons

Difference between Out and Ref keyword in C#

Posted on August 27, 2017 | Leave a comment

https://www.javatpoint.com/c-sharp-call-by-reference

https://www.javatpoint.com/c-sharp-out-parameter

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Posted in C#

.NET Components

Posted on August 25, 2017 | Leave a comment

http://www.developerin.net/a/39-Intro-to-.Net-FrameWork/23-Components-of-.Net-Framework

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Posted in .NET

Calling Method Example in C#

Posted on August 12, 2017 | Leave a comment

code:

with object creation from class:

using System;

namespace CallingMethods
{
    class Program
    {
       int Add(int a, int b)
       {
           int result;
           result = a + b;
           return result;
       }
        static void Main(string[] args)
        {
            int first, second;
            Console.WriteLine("1st number:");
            first=Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("2nd number");
            second = Convert.ToInt32(Console.ReadLine());
            Program obj1=new Program();
            
            int result = obj1.Add(first, second);
            Console.WriteLine("The addition is: "+result);
            Console.ReadKey();
        }
    }
}

using System;

namespace CallingMethods

{

class Program

{

int Add(int a, int b)

{

int result;

result = a + b;

return result;

}

static void Main(string[] args)

{

int first, second;

Console.WriteLine("1st number:");

first=Convert.ToInt32(Console.ReadLine());

Console.WriteLine("2nd number");

second = Convert.ToInt32(Console.ReadLine());

Program obj1=new Program();

int result = obj1.Add(first, second);

Console.WriteLine("The addition is: "+result);

Console.ReadKey();

}

If we don’t want to use object we can use static keyword here:

using System;

namespace CallingMethods
{
    class Program
    {
       static int Add(int a, int b)
       {
           int result;
           result = a + b;
           return result;
       }
        static void Main(string[] args)
        {
            int first, second;
            Console.WriteLine("1st number:");
            first=Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("2nd number");
            second = Convert.ToInt32(Console.ReadLine());
           
            
            int result = Add(first, second);
            Console.WriteLine("The addition is: "+result);
            Console.ReadKey();
        }
    }
}

using System;

namespace CallingMethods

{

class Program

{

static int Add(int a, int b)

{

int result;

result = a + b;

return result;

}

static void Main(string[] args)

{

int first, second;

Console.WriteLine("1st number:");

first=Convert.ToInt32(Console.ReadLine());

Console.WriteLine("2nd number");

second = Convert.ToInt32(Console.ReadLine());

int result = Add(first, second);

Console.WriteLine("The addition is: "+result);

Console.ReadKey();

}

Static method can be invoked with class name:

using System;

namespace CallingMEthods1
{
    class MyClass
    {
        public static void MyMethod()
        {
            Console.WriteLine("Showing From Method");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            MyClass.MyMethod();
            Console.ReadKey();
        }
    }
}

using System;

namespace CallingMEthods1

{

class MyClass

{

public static void MyMethod()

{

Console.WriteLine("Showing From Method");

}

class Program

{

static void Main(string[] args)

{

MyClass.MyMethod();

Console.ReadKey();

}

Can be invoked without creating objects:

using System;

namespace CallingMEthods1
{
    class Program 
    {
        public static void MyMethod()
        {
            Console.WriteLine("Showing From Method");
        }
    
        static void Main(string[] args)
        {
            MyMethod();
            Console.ReadKey();
        }
    }
}

using System;

namespace CallingMEthods1

{

class Program

{

public static void MyMethod()

{

Console.WriteLine("Showing From Method");

}

static void Main(string[] args)

{

MyMethod();

Console.ReadKey();

}

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Posted in C#

Tagged C sharp, OOP

Syed Ahmed Zaki

Abstract class in C#

Polymorphism: Method Overloading and Method Overriding and Method Hiding

Aggregation in OOP

Inheritance in C#

Encapsulation in C#

C# Access Modifiers/Specifiers

C# Structs works almost like a Class !

How many constructor a class have in C# ?

C# usage of Static Keyword

C# Constructor and Destructor

C# Object and Classes

Story, Motivation about Life!

Difference between Out and Ref keyword in C#

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Calling Method Example in C#

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Recent Comments

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My Algorithmic Progress in OJ’s

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Tags

Count per Day

Archives

This site is powered by:

Bookmarks

My Coding Page

Top Posts & Pages

My Skills

My Poster/Presentations

My Videos

My Bookshelf

Quote From Life