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:
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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:
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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! 😀