LINQ 中的过滤运算符
过滤是一种限制结果集的操作,使其仅包含满足特定条件的选定元素。
运算符 | 描述 | C# 查询表达式语法 | VB 查询表达式语法 |
---|---|---|---|
Where | 根据谓词函数过滤值 | where | Where |
OfType | 根据值作为指定类型 | 不适用 | 不适用 |
Where 示例 - 查询表达式
C#
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Operators { class Program { static void Main(string[] args) { string[] words = { "humpty", "dumpty","set", "on", "a", "wall" }; IEnumerable<string> query = from word in words where word.Length == 3 select word; foreach (string str in query) Console.WriteLine(str); Console.ReadLine(); } } }
VB
Module Module1 Sub Main() Dim words As String() = {"humpty", "dumpty", "set", "on", "a", "wall"} Dim query = From word In words Where word.Length = 3 Select word For Each n In query Console.WriteLine(n) Next Console.ReadLine() End Sub End Module
当用 C# 或 VB 编译并执行上述代码时,会产生以下结果 −
set