Csharp/CSharp Tutorial/LINQ/DefaultIfEmpty — различия между версиями
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Admin (обсуждение | вклад) м (1 версия) |
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Текущая версия на 15:18, 26 мая 2010
DefaultIfEmpty Demo
<source lang="csharp">using System; using System.Linq; using System.Collections; using System.Collections.Generic; public class MainClass {
public static void Main() { string[] presidents = {"G", "H", "a", "H", "over", "Jack"}; string name = presidents.Where(n => n.Equals("H")).DefaultIfEmpty("Missing").First(); Console.WriteLine(name); }
}</source>
Using DefaultIfEmpty in Where clause
<source lang="csharp">using System; using System.Linq; using System.Collections; using System.Collections.Generic; public class MainClass {
public static void Main() { string[] presidents = {"G", "H", "a", "H", "over", "Jack"}; string jones = presidents.Where(n => n.Equals("H")).DefaultIfEmpty().First(); if (jones != null) Console.WriteLine("H was found."); else Console.WriteLine("H was not found."); }
}</source>
Without Using DefaultIfEmpty
<source lang="csharp">using System; using System.Linq; using System.Collections; using System.Collections.Generic; public class MainClass {
public static void Main() { string[] presidents = {"G", "H", "a", "H", "over", "Jack"}; string jones = presidents.Where(n => n.Equals("H")).First(); if (jones != null) Console.WriteLine("H was found"); else Console.WriteLine("H was not found"); }
}</source>