C# – LINQ, ForEach, Classes, Override

Some 2.5 years ago I have first written an article for LINQ, when I was learning it. Now, I was watching at some videos about algorithms and I realized I have not used LINQ in quite a while and I have forgotten how it works. Thus, I have decided to make my Sunday evening a little more productive and to write a small program, that can remind me of what I was the LINQ usage 🙂

Thus, lets imagine that we have 6 companies and each one has a name, CEO, profit and country. In order to mimic this idea, I have built up the class Company.cs:

namespace linq_test
{
    class Company
    {
        private string _companyName;
        private string _companyCEO;
        private int _companyProfit;
        private string _companyCountry;

        public Company(string name, string ceo = "No CEO", int profit = 0, string country = "Bulgaria")
        {
            _companyName = name;
            _companyCEO = ceo;
            _companyProfit = profit;
            _companyCountry = country;
        }

        public string name
        {
            get { return _companyName; }
        }

        public int profit
        {
            get {return _companyProfit;}
        }

        public string country 
        {
            get {return _companyCountry;}
        }

        public string ceo
        {
            get
            {
                return _companyCEO;
            }
            set
            {
                _companyCEO = value;
            }
        }

        public override string ToString()
        {
            return string.Format("This company is named {0}. The CEO is {1}. The profit is {2}. It is located in {3}.",
                                this.name, this.ceo, this.profit, this.country);
        }

    }
}

As you see above, I have overridden the ToString method with my own, which I would be using later. Something else worth noting, is that I have optional parameters in the builder and I have setter only for the CompanyCEO name. The rest is standard.

In my other class, called LinqApp.cs I define 6 objects of type Company. Then I use LINQ to build up first the Bulgarian companies only and then only the once with profit above 0. This is what I get:

This is the code from the LinqApp.cs class:

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

namespace linq_test
{
    class LinqApp
    {
        static void Main()
        {
            Company c1 = new Company("VitoshAcademy", "Vitosh", 10, "Bulgaria");
            Company c2 = new Company("VitoshAcademy2", "Vitosh", 12, "Russia");
            Company c3 = new Company("SomeBadCompany", "Vitosh", 14, "Germany");
            Company c4 = new Company("SomeBadCompany2", "Creepy", 16, "Germany");
            Company c5 = new Company("SomeBadCompany3", "Creepy");
            Company c6 = new Company("SomeBadCompany4", "Vitosh");

            List companies = new List { c1, c2, c3, c4, c5, c6 };

            var bulgarian_companies = from my_company in companies
                                      where my_company.country == "Bulgaria"
                                      select my_company;
            Console.WriteLine("Bulgarian companies only:");
            foreach (var company in bulgarian_companies)
            {
                Console.WriteLine(company.ToString());
            }

            Console.WriteLine("\nCompanies with a positive profit :");
            var companies_with_profit = from my_company in companies
                                        where my_company.profit > 0
                                        select my_company;

            foreach (var company in companies_with_profit)
            {
                Console.WriteLine(company.ToString());
            }
        }
    }
}

If you want to see the files in GitHub, here they are! Enjoy! 😀