get & set accessor issue ?

When you create a Class12 object, the constructor initializes the three instance fields with whatever parameters are passed in.

Prior to this, the fields have their default values which is null for strings and zero for doubles.

Well awesome many many thanks friend .. i loved ur explanation 

Just a small query .. Well in C# Every non static data member show be initialized with object right .. @ basic rule .

In the above code you declared 3 non static variable i.e 

             string _last_name;

Well ty friend 

I made the adjustments .. please look into it . code now working properly but i am not confident enough . . so please check it matter of seconds for you :)

class Class12
    {
            static string _last_name;
            static string _first_name;
            static double _gross_pay;


             public  double gross_pay
             {
                 get
                 {
                     return _gross_pay;
                 }
                 set
                 {
                     value = _gross_pay;
                 }
             }
             public string last_name
             {
                 get
                 {
                     return _last_name;
                 }


                 set
                 {
                     value = _last_name;
                 }
             }
             public string first_name
             {
                 get
                 {
                     return _first_name;
                 }


                 set
                 {
                     value = _first_name;
                 }
             }
             public Class12(string _first_name, string _last_name, double _gross_pay)
             {
                 this.first_name = _first_name;
                 this.last_name = _last_name;
                 this.gross_pay = _gross_pay;
             }


    public void adjustPay(double _gross_pay)
    {
        //adjust the pay by multiplying it by a factor of 1.2 
        _gross_pay = _gross_pay * 1.2;
        Console.WriteLine("The adjusted pay is {0} for {1} {2}", _gross_pay,_first_name,_last_name);
    }


        static void Main(string [] args)
        {
            Class12 obj = new Class12(_first_name,_last_name,_gross_pay);
            Console.Write("Enter the first name ");
           _first_name = Console.ReadLine();
            Console.Write("Enter the last name ");
            _last_name = Console.ReadLine();
            Console.Write("Enter the raw pay ");
           _gross_pay = Convert.ToDouble(Console.ReadLine());


         
            obj.adjustPay(_gross_pay);
            Console.WriteLine("Press any key to continue . . .");
            Console.ReadKey();
        }
    }

Actually under constructor i am not sure it can be like this
this.name = _name ???? but i feel it should be like this._name=_name

Well in above declaration i declared the 3 variables with static just becoz to avoid non-static initialization .. 

Please :) check the above code in this comment and give perfect touch up with style . I like the variable declaration non-static 

Thank you

You must give the property a different name to its backing field.

One convention is to start the property name with an upper case letter but the field with a lower case letter.

So you could call the property First_name but the backing field first_name.

Another popular convention is to proceed as above but to prefix the field name with an underscore i.e. _first_name.

However, the latter convention is more commonly used in combination with 'camel' casing. So FirstName for the property and _firstName for the backing field.