Constructor in C#

code:

using System;

namespace Constructor
{
    class Testing
    {

        int marks;
        static int maxmarks=50;

        Testing() //My own default constructor
        {
            this.marks = 30;
        }

        Testing(int marks)//parameterized constructors
        {
            this.marks = marks;
        }

        Testing(Testing t) //copy constructors
        {
            this.marks = t.marks;
        }
        void CalculatePercent()
        {
            int percent = this.marks * 100 / Testing.maxmarks;
            Console.WriteLine(percent);
        }

        static Test() //static vonstructor
        {
            Testing.maxmarks = 50;
        }

        
        static void Main(string[] args)
        {
            Testing t1=new Testing();
            t1.CalculatePercent();
            Testing t2=new Testing(35);
            t2.CalculatePercent();
            Testing t3=new Testing(t2);
            t3.CalculatePercent();

            Testing t4=new Testing(45);
            Testing t5 = t4;
            t4.marks = 60;
            t5.CalculatePercent();

            Console.ReadKey();
        }
    }
}

https://www.dotnetperls.com/constructor

https://www.tutorialspoint.com/csharp_online_training/c_constructors.asp