static void GroupingAndNestedObjects()
{
var countries = from r in Formulal.GetChampions()
group r by r.Country into g
let count = g.Count()
orderby count descending, g.Key
where count >= 2
select new
{
Country = g.Key,
Count = coung,
Racers = from r1 in g
orderby r1.LastName
select r1.FirstName + " " + r1.LastName
};
foreach (var item in countries)
{
Console.WriteLine($"{item.Country,-10}{item.Count}");
foreach (var name in item.Racers)
{
Console.WriteLine(name);
}
Console.WriteLine();
}
}
static void CompoundFrom()
{
var ferrariDrivers = from r in Formulal.GetChampions()
from c in r.Cars
where c == "F"
orderby r.LastName
select r.FirstName + " " + LastName;
}
static void Filtering()
{
var racers = from r in Formulal.GetChampions()
where r.Wins > 15 && (r.Country == "B" || r.Country == "A")
select r;
foreach (var item in racers)
{
Console.WriteLine(item);
}
}
static void ToLookup()
{
var racers = (from r in Formulal.GetChampions() from c in r.Cars select new { Car = c, Racer = r }).ToLookup(cr => cr.Car, cr => cr.Racer);
if (racers.Contains("Williams"))
{
foreach (var item in racers["Williams"])
{
Console.WriteLine(item);
}
}
}
static void ToList()
{
List <Racer> racers = (from r in Formulal.GetChampions()
where r.Statrts > 200
orderby r.Starts descending
select r).ToList();
foreach (var item in racers)
{
Console.WriteLine(item);
}
}
static void Grouping()
{
var countries = from r in Formulal.GetChampions()
group r by r.Country into g
orderby g.Count() descending, g.key
where g.Count() >= 2
select new
{
Country = g.Key,
Count = g.Count()
};
}
static void LinqQuery()
{
var query = from r in Formulal.GetChampions()
where r.Country == "Brazil"
orderby r.Wins descending
select r;
foreach (var r in query)
{
Console.WriteLine($"{r:A}");
}
}
static void GroupingWithAnonymousTypes()
{
var countries = Formulal.GetChampions().GroupBy(r => r.Country)
.Select(g => new { Group = g, Count = g.Count() })
.OrderByDescending(g => g.Count)
.ThenBy(g => g.Group.Key)
.Where(g => g.Count >= 2)
.Select(g => new
{
Country = g.Group.Key,
Count = g.Count
});
}
static void GroupingWithVariables()
{
var countries = from r in Formulal.GetChampions()
group r by r.Country into g
let count = g.Count()
orderby count descending, g.key
where count >= 2
select new
{
Country = g.Key,
Count = count
};
}
static void GroupingWithMethods()
{
var countries = Formulal.GetChampions()
.GroupBy(r => r.Country)
.OrdertByDescending(g => g.Count())
.ThenBy(g => g.Key)
.Where(g => g.Count() >= 2)
.Select(g => new
{
Country = g.Key,
Count = g.Count
});
}
static void ConverWithCast()
{
var list = new System.Conllections.ArrayList(Formulal.GetChampions() as System.Collections.ICollection);
var query = from r in list.Cast <Racer>()
where r.Country == "USA"
orderby r.Wins descending
select r;
foreach (var item in query)
{
Console.WriteLine($"{item:A}");
}
}
static void Partitioning()
{
int pageSize = 5;
int numberPages = (int)Math.Ceiling(Formulal.GetChampions().Count() / (double)pageSize);
for (int i = 0; i < numberPages; i++)
{
Console.WriteLine(i);
var racers = (from r in Formulal.GetChampions() orderby r.LastName, r.FirstName select r.FirstName + " " + r.LastName).Skip(pageSize * pageSize).Take(pageSize);
foreach (var item in racers)
{
Console.WriteLine(item);
}
}
}
static void AggregateCount()
{
var query = from r in Formulal.GetChampions()
let numberYears = r.Years.Count()
where numberYears >= 3
orderby numberYears descending, r.LastName
select new
{
Name = r.FirstName + " " + r.LastName,
TimeChampion = numberYears
};
foreach (var item in query)
{
Console.WriteLine($"{item.Name}{item.TimeChampion}");
}
}
static void GroupingAndNestedObjectsWithMethods()
{
var countries = Formulal.GetChampions().GroupBy(r => r.Country)
.Select(g => new {
Group = g,
Key = g.Key,
Count = g.Count()
})
.OrderByDescending(g => g.Count)
.ThenBy(g => g.Key)
.Where(g => g.Count >= 2)
.Select(g => new
{
Country = g.Key,
Count = g.Count,
Racers = g.Group.OrderBy(r => r.LastName),
.Select(r => r.FirstName + " " + r.LastName)
});
static void ExtensionMethods()
{
var champions = new List <Racer>(Formulal.GetChampions());
IEnumerable <Racer> brazilChampions = champions.Where(r => r.Country == "Brazil").OrderByDescending(r => r.Wins).Select(r => r);
foreach (var item in brazilChampions)
{
Console.WriteLine($"{item:A}");
}
var names = new List <string> {
"a", "B", "C", "d"
};
var namesWithJ = (from n in names where n.StartsWith("a") orderby n select n).ToList();
Console.WriteLine("First iteration");
foreach (string name in namesWithJ)
{
Console.WriteLine(name);
}
}
static void CompoundFromWithMethods()
{
var ferrariDrivers = Formulal.GetChampions().SelectMany(r => r.Cars, (r, c) => new { Racer = r, Car = c }).Where(r => r.Car = "F").OrderBy(r => r.Racer.LastName).Select(r => r.Racer.FirstName + " " + r.Racer.LastName);
}