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Operatoren

Distinct​

  • Keine doppelten Werte in Liste

Abfragesyntax​

var query15 = (from c in cities
               select c).Distinct();

foreach (var item in query15)
    Console.WriteLine($"City: {item.CityName}");

Erweiterungsmethodensyntax​

var query16 = cities.Distinct();

foreach (var item in query16)
    Console.WriteLine($"City: {item.CityName}");

Union​

  • Zwei Listen verbinden
  • doppelte Werte ignorieren.

Abfragesyntax​

string[] otherFirstNames = { "Anne", "David", "Max", "Ludger" };

var query17 = (from c in customers
                select new { c.Firstname }).Union(
                    from o in otherFirstNames
                    select new { Firstname = o });

foreach (var item in query17)
    Console.WriteLine($"Firstname: {item.Firstname}");

Erweiterungsmethodensyntax​

string[] otherFirstNames = { "Anne", "David", "Max", "Ludger" };

var query18 = customers
                .Select(c => new { c.Firstname })
                .Union(
                    otherFirstNames
                        .Select(o => new { Firstname = o }));

foreach (var item in query18)
    Console.WriteLine($"Firstname: {item.Firstname}");

Intersect​

  • Zwei Listen verbinden
  • Nur Werte in neuer Liste, die in beiden vorkommen

Abfragesyntax​

string[] otherFirstNames2 = { "Anne", "David", "Max", "Ludger", "Julia" };

var query19 = (from c in customers
                select new { c.Firstname }).Intersect(
                    from o in otherFirstNames2
                    select new { Firstname = o });

foreach (var item in query19)
    Console.WriteLine($"Firstname: {item.Firstname}");

Erweiterungsmethodensyntax​

string[] otherFirstNames2 = { "Anne", "David", "Max", "Ludger", "Julia" };

var query20 = customers
                .Select(c => new { c.Firstname })
                .Intersect(
                    otherFirstNames2
                        .Select(o => new { Firstname = o }));

foreach (var item in query20)
    Console.WriteLine($"Firstname: {item.Firstname}");

Except​

  • Zwei Listen verbinden
  • Nur Werte in neuer Liste, die sich unterscheiden

Abfragesyntax​

string[] otherFirstNames3 = { "Anne", "David", "Max", "Ludger", "Julia" };

var query21 = (from c in customers
                select new { c.Firstname }).Except(
                    from o in otherFirstNames3
                    select new { Firstname = o });

foreach (var item in query21)
    Console.WriteLine($"Firstname: {item.Firstname}");

Erweiterungsmethodensyntax​

string[] otherFirstNames3 = { "Anne", "David", "Max", "Ludger", "Julia" };

var query22 = customers
                .Select(c => new { c.Firstname })
                .Except(
                    otherFirstNames2
                        .Select(o => new { Firstname = o }));

foreach (var item in query22)
    Console.WriteLine($"Firstname: {item.Firstname}");

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