public static List <Racer> TraditionalQuery()
{
List <Racer> racers = new List <Racer>(Formula1.GetChampions());
List <Racer> brazilRacers = racers.FindAll(delegate(Racer r)
{ return(r.Country == "Brazil"); });
brazilRacers.Sort(
delegate(Racer r1, Racer r2)
{
return(r2.Wins.CompareTo(r1.Wins));
});
return(brazilRacers);
}
public static IEnumerable <Racer> LambdaExpressions()
{
IEnumerable <Racer> brazilChampions =
Formula1.GetChampions().
Where(r => r.Country == "Brazil").
OrderByDescending(r => r.Wins).
Select(r => r);
/*
* foreach (Racer r in brazilChampions)
* {
*
* Console.WriteLine("{0:A}, r");
* }
*/
return(brazilChampions);
}
public static IEnumerable <Racer> LinqQuery()
{
var query = from r in Formula1.GetChampions()
where r.Country == "Brazil"
orderby r.Wins descending
select r;
//Filtering
var races = from r in Formula1.GetChampions()
where r.Wins > 15 && (r.Country == "Brazil" || r.Country == "Austria")
select r;
//Filtering with lambda expression
var racers = Formula1.GetChampions().Where(r => r.Wins > 15 && (r.Country == "Brazil" || r.Country == "Austria")).Select(r => r);
//Filtering with index
var racerss = Formula1.GetChampions().Where((r, index) => r.LastName.StartsWith("A") && index % 2 != 0);
//Type Filtering
object[] data = { "one", 2, 3, "four", "five", 6 };
var myquery = data.OfType <string>();
foreach (var s in query)
{
Console.WriteLine(s);
}
//Compound form
var ferrariDrivers = from r in
Formula1.GetChampions()
from c in r.Cars
where c == "Ferrari"
orderby r.LastName
select r.FirstName + " " + r.LastName;
//SelectMany
var ferrariDriversMany = Formula1.GetChampions().
SelectMany(r => r.Cars, (r, c) => new { Racer = r, Car = c }).
Where(r => r.Car == "Ferrari").
OrderBy(r => r.Racer.LastName).
Select(r => r.Racer.FirstName + " " + r.Racer.LastName);
//Sorting Linq
var racersSortingLinq = from r in Formula1.GetChampions()
where r.Country == "Brazil"
orderby r.Wins descending
select r;
//Sorting Lamba (extansion methods)
var racersSortingLambda = Formula1.GetChampions().
Where(r => r.Country == "Brazil").
OrderByDescending(r => r.Wins).
Select(r => r);
//Take
var racersTake = (from r in Formula1.GetChampions()
orderby r.Country, r.LastName, r.FirstName
select r).Take(10);
//Take with extension methods Lambda
var racersTakeLambda = Formula1.GetChampions().
OrderBy(r => r.Country).
ThenBy(r => r.LastName).
ThenBy(r => r.FirstName).
Take(10);
//Grouping
var countries = from r in Formula1.GetChampions()
group r by r.Country into g
orderby g.Count() descending, g.Key
where g.Count() >= 2
select new { Country = g.Key, Count = g.Count() };
//Gouping with extension methods Lambda
var countriesLambda = Formula1.GetChampions().
GroupBy(r => r.Country).
OrderByDescending(g => g.Count()).
ThenBy(g => g.Key).
Where(g => g.Count() >= 2).
Select(g => new { Country = g.Key, Count = g.Count() });
return(racersTake);
}
