Define Object Ex. 01

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

namespace _01.GSM_All_In_One
{
    class Battery
    {

        public string Model { get; set; }
        public double? Idle { get; set; }
        public double? Talk { get; set; }



        //Print all Battery information
        public void Print()
        {
            Console.WriteLine("Battery Properties");
            Console.WriteLine("===================");
            Console.WriteLine("Model: {0}", this.Model);
            Console.WriteLine("Idle hours: {0}:{1,2} hours", (int)this.Idle, (this.Idle - (int)this.Idle)*60);
            Console.WriteLine("Talk hours: {0}:{1,2} hours", (int)this.Talk, (this.Talk - (int)this.Talk)*60);
            Console.WriteLine("===================");
        }

    }
    class Display
    {
        public double? Size { get; set; }
        public double? Colors { get; set; }

        //print all Display information
        public void Print()
        {
            Console.WriteLine("Display Properties");
            Console.WriteLine("===================");
            Console.WriteLine("Size: {0}''", this.Size);
            Console.WriteLine("Colors: {0} millions", this.Colors);
            Console.WriteLine("===================");
        }

    }
    class GSM
    {
        public string Model { get; set; }
        public string Manafacturer { get; set; }
        public decimal Price { get; set; }
        public string Owner { get; set; }


        public Battery Battery = new Battery();

        public Display Display = new Display();

        //Print all GSM information
        public void Print()
        {
            Console.WriteLine("GSM Properties");
            Console.WriteLine("===================");
            Console.WriteLine("Model: {0}", this.Model);
            Console.WriteLine("Manafacturer: {0}", this.Manafacturer);
            Console.WriteLine("Owner: {0}", this.Owner);
            Console.WriteLine("Price: {0} EUR", this.Price);
            Console.WriteLine("===================");

        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            GSM myGSM = new GSM(); //by default all the value are null
            myGSM.Model = "3310";
            myGSM.Manafacturer = "Nokia";
            myGSM.Owner = "Kiril Petrov"; //fake name :)
            myGSM.Price = 345.21m;

            myGSM.Battery.Model = "Belkin";
            myGSM.Battery.Idle = 6.5; //hours in idle mode of type double
            myGSM.Battery.Talk = 1.5; //hours in talk mode of type double

            myGSM.Display.Size = 7.4; //size in inches
            myGSM.Display.Colors = 16.5; //colors in millions

            myGSM.Print(); //print GSM properties
            myGSM.Battery.Print(); //print Battery properties
            myGSM.Display.Print(); //print Display properties

        }
    }
}