I am currently studying on multiple inheriting operation.What ihave learnt is we can’t inherit multiple class but we can inherit a class and an interface so i just need to switch a class to an interface. Like below

class a{} class b{} interface d{} //class c:a,b{} That does not work //class c:a,d{} or class c:b,d{} but these need to work 

If i return to my question respect for multiple inheritance operation, Here is an complete program that explains my problem.

using System;   using System.Collections.Generic;   using System.Text;  namespace interface_ile_multiple_inheritance   {   interface set_get {     double _getx     { get; }     double _gety     { get ; }      protected double total;//I want to use it by inheriting   } class set_items {     protected double x;     protected double y;     public set_items(double _x, double _y)     {         x = _x;         y = _y:      }    } class display : set_items, set_get {        public display(double x, double y) : base(x, y) { }       public  double _getx     { get { return x; } }     public double _gety     { get { return y; } }      public double total_res()     {         total = x + y;    // Error line 1 total does not exist          return total;     //Error line 2 total does not exist       }  }    class Program {     static void Main(string[] args)     {           display disp1 = new display(12, 12);          Console.WriteLine("Total:" + disp1.total_res().ToString());//HERE İ NEED TO FİND x+y         Console.WriteLine("Area:" + (disp1._getx * disp1._gety).ToString());//HERE İ NEED TO FİND x*y       } } 

}

Even though i can inherit interface’s property signatures,why can’t i inherit its integer variable?