Simple linq : foreach loop « LINQ « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. LINQ
3. foreach loop

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

    public class Customer
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string EmailAddress { get; set; }

        public override string ToString()
        {
            return string.Format("{0} {1}\nEmail:   {2}",FirstName, LastName, EmailAddress);
        }
    }
    public class Tester
    {
        static void Main()
        {
            List<Customer> customers = new List<Customer>{
                    new Customer { FirstName = "A", 
                                    LastName = "B",
                                    EmailAddress = "o@a.com"},
                    new Customer { FirstName = "B", 
                                    LastName = "C",
                                    EmailAddress = "k@a.com" },
                    new Customer { FirstName = "D", 
                                    LastName = "C",
                                    EmailAddress = "d@a.com" },
                    new Customer { FirstName = "F", 
                                    LastName = "G",
                                    EmailAddress = "j@a.com" },
                    new Customer { FirstName = "L", 
                                    LastName = "H",
                                    EmailAddress = "l@a.com" }
                };

            IEnumerable<Customer> result =
                from customer in customers
                where customer.FirstName == "Donna"
                select customer;

            foreach (Customer customer in result)
                Console.WriteLine(customer.ToString());

            customers[3].FirstName = "Donna";

            foreach (Customer customer in result)
                Console.WriteLine(customer.ToString());
        }
    }