Linq to return ALL pairs of elements from two lists?

Question

Given lists l1 = {1, 2} and l2 = {4, 5, 6 } I want to get a new list that has elements:

rez = { {1, 4}, {1, 5}, {1, 6}, {2, 4}, {2,         


        

Answer 1

You want

l1.Join(l2, a => 1, b => 1, (a, b) => new [] { a, b });

Answer 2

Here you go;

var rez =  from first in l1 
           from second in l2 
           select new[] { first, second };

Answer 3

Great article by Eric Lippert - see links in other answers. What's even better, this was the first try I did before looking at the answers on this page :)

In short:

var rez = 
    from e1 in l1
    from e2 in l2 
    select new {e1, e2};

Answer 4

something like this will do what you are looking for.

var l1 = new List<int>{1,2};
var l2 = new List<int>{4,5,6};

var p = from n in l1
        from m in l2
        select new { Fst = n, Scd = m };

with this answer your tuples {x,y} are an anonymous type.

Answer 5

Eric Lippert's already done it for you!

http://blogs.msdn.com/b/ericlippert/archive/2010/06/28/computing-a-cartesian-product-with-linq.aspx

you probably just want to the linq fluent syntax of SelectMany

var s1 = new[] {a, b}; 
var s2 = new[] {x, y, z}; 


var product = 
from first in s1 
from second in s2 
select new[] { first, second };

product.SelectMany(o=>o);

or Eric's blog post version

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; 
}

product.CartesianProduct();

Answer 6

var result = from a in l1
             from b in l2
             select new[] { a, b }