cs oop 006 Consructor with Different Parametyrs

using System;
public class Collar
{
    // Static field, holding the current sequence value
    private int c = 0;
    // Intentionally deny instantiation of this class
    public Collar()
    {
    }
}

class Dog
{
    private string name;
    private int age;
    private double length;
    private Collar collar;// Field name


    // No parameters
    public Dog()
    {
        this.name = "Sharo";
        this.age = 1;
        this.length = 0.3;
        this.collar = new Collar();
    }
    // One parameter
    public Dog(string name)
    {
        this.name = name;
        this.age = 1;
        this.length = 0.3;
        this.collar = new Collar();
    }
    // Two parameters
    public Dog(string name, int age)
    {
        this.name = name;
        this.age = age;
        this.length = 0.3;
        this.collar = new Collar();
    }
    // Three parameters
    public Dog(string name, int age, double length)
    {
        this.name = name;
        this.age = age;
        this.length = length;
        this.collar = new Collar();
    }
    // Four parameters
    public Dog(string name, int age, double length, Collar collar)
    {
        this.name = name;
        this.age = age;
        this.length = length;
        this.collar = collar;
    }

    static void Main()
    {
        Dog myDog = new Dog("Bobi", 2, 0.4); // Three parameters Constructors

        Console.WriteLine("My dog " + myDog.name +
              " is " + myDog.age + " year(s) old. " +
                    " and it has length: " + myDog.length + " m");
        Console.ReadKey();
    }
}