Instance constructors in C# Part 1
In this article we will learn about Instance constructors in C#.
Introduction
Constructor is a special method of the class that will be invoked automatically when an instance of the class is created.
Instance constructors
There are four types of instance constructors in C# language.
Default constructor
A constructor that has no parameters is called the default constructor in C#. Each class has a default constructor. Default constructor is used when we want to initialize values of class members. Constructor has same name as class name.
Syntax
public classname()
{
}
Example
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace DefaultConstractor
{
class Rahul
{
int x,y;
public Rahul() //default contructor
{
x = 10;
y = 11;
}
public static void Main()
{
Rahul obj = new Rahul(); //an object is created , constructor is called
Console.WriteLine(obj.x);
Console.WriteLine(obj.y);
Console.ReadLine();
}
}
}
The output of following program
Parameterized Constructor
A constructor that has at least one parameter is called the Parameterized Constructor in C#. Parameterized Constructor is used when we want to initialize each instance of the class to different values.
Syntax
public classname(parameter x)
{
}
Example
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Constructor
{
class Rahul
{
public int P, Q;
public Rahul(int x, int y) // decalaring Paremetrized Constructor with passing x,y parameter
{
P = x;
Q = y;
}
}
class MainClass
{
static void Main()
{
Rahul v = new Rahul(10, 11); // Creating object of Parameterized Constructor and passing values
Console.WriteLine("P is =" + v.P );
Console.WriteLine("Q is =" + v.Q);
Console.ReadLine();
}
}
}
The output of following program