可枚舉連接 - 連接兩個列表

Question

我有兩個列表（列表）具有以下數據：

列表中的一個

James 
Jack 
Laura 
Harry 

列出兩種

Jeffery 
Peters 
Smith 

是它可能使用Enumerable Join做一個Join，以執行以下操作：

James Jeffery 
James Peters 
James Smith 
Jack Jeffery 
Jack Peters 
Jack Smith 
Laura Jeffery 
Laura Peters 
Laura Smith 
Harry Jeffery 
Harry Peters 
Harry Smith 
Harry Jeffery 

這是什麼類型的加入？

Answer 1

這是一個交叉聯接：

List<string> textLines1 = new List<string>() { 
    "Kames", "Jack", "Laura", "Harry" 
}; 
List<string> textLines2 = new List<string>() { 
    "Jeffery", "Peters", "Smith" 
}; 

var query = from t1 in textLines1 
      from t2 in textLines2 
      select string.Format("{0} {1}", t1, t2); 

var results = query.ToList(); 

返回你所期望的。

它也可以使用基於查詢的方法做：

var query2 = textLines1.SelectMany(t1 => textLines2, (t1, t2) => string.Format("{0} {1}", t1, t2)); 

var results2 = query2.ToList(); 

Answer 2

在LINQ這將是：

List<string> TabOne = new List<string>() { "Kames", "Jack", "Laura", "Harry" }; 
List<string> TabTwo = new List<string>() { "Jeffery", "Peters", "Smith" }; 

var combo = from p in TabOne 
     from c in TabTwo 
     select new 
     { 
      Name = p, 
      SurName = c 
     }; 

它被稱爲交叉聯接。

Answer 3

var l1 = new []{ "James", "Jack", "Laura", "Harry" }; 
var l2 = new []{ "Jeffery", "Peters", "Smith" }; 

var result = from i1 in l1 
      from i2 in l2 
      select i1 + " " + i2; 

Answer 4

這也被稱爲Cartesian Product和Eric有blog post about it。

Answer 5

你可以試試這個方法：

var result = list1.SelectMany(i1 => list2.Select(i2 => i1 + " " + i2)); 

例子：

class Program 
{ 
    public static void Main() 
    { 
     string[] list1 = new[] { "James", "Jack", "Laura", "Harry" }; 
     string[] list2 = new[] { "Jeffery", "Peters", "Smith" }; 
     var result = list1.SelectMany(i1 => list2.Select(i2 => i1 + " " + i2)); 

     foreach (string s in result) 
     { 
      Console.WriteLine(s); 
     } 
    } 
} 

APP輸出：

James Jeffery 
James Peters 
James Smith 
Jack Jeffery 
Jack Peters 
Jack Smith 
Laura Jeffery 
Laura Peters 
Laura Smith 
Harry Jeffery 
Harry Peters 
Harry Smith