GSM.cs

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


    class GSM
    {
        private string phoneModel;
        private string phoneManafacturer;
        private string phoneOwner;
        private decimal? phonePrice;

        public GSM(string phoneModel, string phoneManafacturer, string phoneOwner, decimal? phonePrice)
        {
            this.phoneModel = phoneModel;
            this.phoneManafacturer = phoneManafacturer;
            this.phoneOwner = phoneOwner;
            this.phonePrice = phonePrice;
        }

        public static void GetPhoneInfo()
        {

            Console.Write("Type in phone manafacturer: ");
            string manafacturer = Console.ReadLine();

            Console.Write("Type in phone model: ");
            string Model = Console.ReadLine();


            Console.WriteLine("Type in phone owner: ");
            string owner = Console.ReadLine();

            Console.WriteLine("Type in phone price: ");
            decimal? price = Convert.ToDecimal(Console.ReadLine());
            GSM phone=new GSM(Model,manafacturer,owner,price);
            GSM phone2 = new GSM(Model, manafacturer, owner, price);
            Battery.Main1();
            Display.GetDisplayInfo();




        }

        public override string ToString()
        {

            StringBuilder Info = new StringBuilder();
            Info.Append("Phone manafacturer: " + phoneManafacturer);
            Info.ApInfo.Append();pend(" Phone del: " + phoneModel);
            Info.Append("Phone owner: " + phoneOwner);
            Info.Append("Phone price: " + phonePrice);

            //return base.ToString();


        }

        static void Main()
        {
            GetPhoneInfo();


        }


    }