Constructors

What Is a Constructors??

1. Constructor is Basically a function
2. But this function has a name same as that of class name
3. Constructors has no return types
4. The Constructor is called when the instance of the class that is the object is created.

We can say that only use of constructors is to initialize the values whenever an object is called

To understand the concept we will be looking at two programs in this blog.

• Program 1:

               In this program we will be explicitedly create a function that will initialize the value whenever the function is called.

• Program 2:

              In this program we will be creating a constructor that will automatically initialize the value at the time of creation of class without even calling it.

• Program 3:

               In this program we will create constructors with parameters.We will just modify the Program 2 not a big deal


So Here goes the Program 1:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace constructors1
{
    class check
    {
        int num1, num2,num3;
        void initialize() //We are creating a function that will initialise the values
        {
            num1 = 20;
            num2 = 30;

        }

        void add_nunmbers()
        {
            num3 = num1 + num2;
        }

        void display()
        {
            Console.WriteLine("The addition of the numbers 20 and 30 is {0}",num3);
        }
        static void Main(string[] args)
        {
            check c1=new check();
            c1.initialize();//We are calling the function to initialize
            c1.add_nunmbers();
            c1.display();
            Console.ReadLine();
           
        }
    }
}

Program 2:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace constructors1
{
    class Constructor
    {
        int num1, num2, num3;
        Constructor() //We are creating a function that has the name same as that of the class this will initialise the values
        {
            num1 = 20;
            num2 = 30;

        }

        void add_nunmbers()
        {
            num3 = num1 + num2;
        }

        void display()
        {
            Console.WriteLine("The addition of the numbers 20 and 30 is {0}", num3);
        }
        static void Main(string[] args)
        {
            Constructor c1 = new Constructor();//This will automaitcally initialize the values
          
            c1.add_nunmbers();
            c1.display();
            Console.ReadLine();

        }
    }
}

Program 3: Here we will be using inputs from the user.

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

namespace constructors1
{
    class Constructor
    {
        int num1, num2, num3;
        Constructor(int number1,int number2) //We are creating a constructor with parameter
        {
            num1 = number1;
            num2 = number2;

        }

        void add_nunmbers()
        {
            num3 = num1 + num2;
        }

        void display()
        {
            Console.WriteLine("The addition of the numbers {0} and {1} is {2}",num1,num2, num3);
        }
        static void Main(string[] args)
        {
            Console.WriteLine("Enter Two Numbers to be Added");
            int n1, n2;
            n1 = Convert.ToInt32(Console.ReadLine());
            n2 = Convert.ToInt32(Console.ReadLine());
            Constructor c1 = new Constructor(n1,n2);//caling the constructors with parameters
            c1.add_nunmbers();
            c1.display();
            Console.ReadLine();

        }
    }
}