连接3单词列表

Question

我想弄清楚如何使用C＃创建单个连接列表，源自3个单独的列表。例如：

List 1: Ugly, Pretty 
List 2: Dogs, Carts, Pigs 
List 3: Rock, Suck 

输出：

Ugly Dogs Rock 
Ugly Dogs Suck 
Ugly Cats Rock 
Ugly Cats Suck 
Ugly Pigs Rock 
Ugly Pigs Suck 
Pretty Dogs Rock 
Pretty Dogs Suck 
Pretty Cats Rock 
Pretty Cats Suck 
Pretty Pigs Rock 
Pretty Pigs Suck 

我知道这只是个嵌套循环，但我不能找出部分是如何使用List串每个列表。

Answer 1

var list = from s1 in list1 
      from s2 in list2 
      from s3 in list3 
      select s1 + " " + s2 + " " + s3; 

Answer 2

它不是笛卡儿的产品吗？

var r = from i1 in list1 
     from i2 in list2 
     from i3 in list3 
     select new { i1, i2, i3 }; 
     // or String.Format("{0} {1} {2}", i1, i2, i3); 

Answer 3

List<string> list1 = new List<string>(){ "Ugly", "Pretty"}; 
List<string> list2 = new List<string>(){ "Dogs", "Carts", "Pigs"}; 
List<string> list3 = new List<string>(){ "Rock", "Suck"}; 

var result = from s1 in list1 
      from s2 in list2 
      from s3 in list3 
      select new[] { s1, s2, s3 }; 

foreach (var item in result) 
{ 
    Console.WriteLine(String.Join(",", item)); 
} 

如果你正在寻找一个更通用的解决方案，不仅为3所列出您可以尝试埃里克利珀的解决方案

foreach (var item in new[] { list1, list2, list3 }.CartesianProduct()) 
{ 
    Console.WriteLine(String.Join(",", item)); 
} 

---

public static partial class MyExtensions 
{ 
    // Eric Lippert’s Blog 
    // Computing a Cartesian Product with LINQ 
    // http://blogs.msdn.com/b/ericlippert/archive/2010/06/28/computing-a-cartesian-product-with-linq.aspx 
    public static IEnumerable<IEnumerable<T>> CartesianProduct<T>(this IEnumerable<IEnumerable<T>> sequences) 
    { 
     // base case: 
     IEnumerable<IEnumerable<T>> result = new[] { Enumerable.Empty<T>() }; 
     foreach (var sequence in sequences) 
     { 
      var s = sequence; // don't close over the loop variable 
      // recursive case: use SelectMany to build the new product out of the old one 
      result = 
       from seq in result 
       from item in s 
       select seq.Concat(new[] { item }); 
     } 
     return result; 
    } 
}