Updated on Kisan Patel
The group operator transforms sequence into a sequence of groups.
The group operator can be used to project a result grouped by a key. It can be used as an alternative to the from clause and allows you to use single-value keys as well as multiple-value keys.
The group operator implements IGrouping<TKey, T> interface.
The group operator will end a query, use into to continue the query.
For Example,
var query = from c in customers
group customers by c.City
into groupbyCities
orderby groupbyCities.Key ascending
select groupbyCities;
Let’s take example to understand how group operator works.
using System;
using System.Collections.Generic;
using System.Linq;
namespace ConsoleApp
{
class Program
{
static void Main(string[] args)
{
List customers = new List{
new Customer{ Id = 1, Name = "Kisan", City="Ladol" },
new Customer{ Id = 2, Name = "Kite", City = "Ladol" },
new Customer{ Id = 3, Name = "Ketul", City = "Vijapur" },
new Customer{ Id = 4, Name = "Kisan", City = "Vijapur" },
};
var query = from c in customers
group c by c.City;
foreach (var group in query)
{
Console.WriteLine("Group City : " + group.Key);
foreach (var name in group)
{
Console.WriteLine(name.Id + " - " + name.Name);
}
}
}
}
public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public string City { get; set; }
}
}
the output of the above C# program…
