Passing Arguments to Function in C#

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

namespace ConsoleApplication
{
    public class Program
    {
        public string name;
        public int rollno;
        public void setname(string n) //passing here argument to parameter
        {                                //'n'.
            name = n; //passed value assigning to 'name'.
        }
        public void setrollno(int rn) //passing here in parameter
        {                            //to 'rn',in function.
            rollno = rn; //passed value assigning to 'rollno'.
        }
        public void showname() //'showname' is function name.
        {
            Console.WriteLine(name); //used for printing 'name' value.
        }
        public void showrollno() //'showrollno' is function.
        {
            Console.WriteLine(rollno); //used for printing 'rollno' value.
        }
        static void Main(string[] args)
        {
            Program p = new Program();
            p.setname("HiLaLs"); //passing argument'HiLaLs' to parameter
            //'n' through function.
            p.setrollno(120122067);//passing '120122067' to parameter
            //'rn' through function.
            p.showname(); //calling 'showname' function.
            p.showrollno(); //calling 'showrollno' function.
            Console.ReadKey();
        }
    } //here used 'public string name', and 'public int rollno', there are
}

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

namespace ConsoleApplication1
{
    public class Program
    {
        public string name;
        public int rollno;
        public void set(string n, int rn)
        {
            name = n;
            rollno = rn;
        }
        public void show()
        { //if U write 'Console.WriteLine(name,rollno);'
          //then it not working it printing only 'name'.
		  //then write like 'Console.WriteLine(name +"\n"+ rollno);', U also write
		  //without '\n' like 'Console.WriteLine(name +""+ rollno);'.
            Console.WriteLine(name);
            Console.WriteLine(rollno);
        }
        static void Main(string[] args)
        {
            Program p = new Program();
            p.set("HiLaLs",120122067);
            p.show();
            Console.ReadKey();
        }
    }
}

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

namespace ConsoleApplication
{
    public class Program
    {
        public int length, height;
        public void set(int l, int h) //passing here Arguments 5 and 10.
        { //'length' and 'height' is not key word.
            length = l;
            height = h;
        }
        public void show()
        { //the formula of Rectangle is 'Length * Height'.
            Console.WriteLine(length * height);
        } //U also write for printing 'The Rectangle is: 50' write like
		 //'Console.WriteLine("The Rectangle is: {0}",length * height);'.
        static void Main(string[] args)
        {
            Program p = new Program();
            p.set(5, 10); //5 is length and 10 is height, and passing to Parameter 'l' and 'h'.
            p.show();
            Console.ReadKey();
        }
    }
}