Get individual items of LINQ Cartesian Product

Question

var A = new[] {A, B}; 
var B = new[] {X, Y, Z}; 
var Product = 
from _A in A 
from _B in B 
select new[] { _A, _B };
//Intent below:
foreach (pair in Product)
{
SomeFunction(pair[0],pair[1])
}

//Output:
SomeFunction(A,X)
SomeFunction(A,Y)
SomeFunction(A,Z)
SomeFunction(B,X)
SomeFunction(A,Y)
SomeFunction(A,Z)

Instead of combining the two lists into one item, how do I retrieve _A & _B as independent variables? So that for each Cartesian cross product combination (A,X..A,Y..A,Z..and so on) I can send them into another function to process?

Ideally, these variables will not be strings so any workarounds with getting character @ indicies will not work.

EDIT: Looks like I was right all along. Thank you for the community for confirming my intent.

Your code looks right to me with the description you've given. What are you seeing that isn't what you're expecting? — Greg B, Dec 05 '18 at 15:38
You're already calling `SomeFunction` with each pair. Are you wanting to avoid the `foreach`? — Richard, Dec 05 '18 at 15:38
Hey Guys, I suppose I just wanted to be 100% sure as I'm not able to debug at the moment and I'm not familiar enough with the Cartesian method of pairing things. So in my example by calling ele[0] I am getting the _A of the [0] item in Product and ele[1] is the _B of [0] in Product? — AndyBernard, Dec 05 '18 at 15:44
@Richard Hey Rich any way to reduce more loops is always welcome too! — AndyBernard, Dec 05 '18 at 15:44

Greg B · Accepted Answer · 2018-12-05T15:48:46.507

-1

I think you're 95% there, and in putting your example together you're 99% there.

Your query will give you the cartesian product as you desire.

var A = new[] {A, B}; 
var B = new[] {X, Y, Z}; 
var Product = from _A in A 
              from _B in B 
              select new[] { _A, _B };

Product is now and IEnumerable<T>. It would look like this:

[
    [A, X]
    [A, Y]
    [A, Z]
    [B, X]
    [B, Y]
    [B, Z]
]

All you need to do now is enumerate it's values, which you have in your intent (though the variable name is wrong):

//Intent below:
foreach (pair in Product)
{
    SomeFunction(pair[0], pair[1]);
}

edited Dec 05 '18 at 15:48

answered Dec 05 '18 at 15:43

Greg B

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appreciate the help. Indeed the ele is wrong I shall update! But again it was more psdeuocode as I was typing I just wanted to confirm it was the right intent. I shall try and let you know! – AndyBernard Dec 05 '18 at 15:50

Get individual items of LINQ Cartesian Product

1 Answers1