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C# Querying With LINQ Query Operators Joins

Nathan Reinauer
Nathan Reinauer
2,097 Points
Posted by Nathan Reinauer
Nathan Reinauer
2,097 Points

Unexpected symbol ',', expecting ')'

I'm probably missing something stupid, but I can't see it. Where do I have a comma that's supposed to be a closing parenthesis?

CodeChallenge.cs 
var myBirds = new List<Bird> 
{ 
    new Bird { Name = "Cardinal", Color = "Red", Sightings = 3 },
    new Bird { Name =  "Dove", Color = "White", Sightings = 2 },
    new Bird { Name =  "Robin", Color = "Red", Sightings = 5 }
};

var yourBirds = new List<Bird> 
{ 
    new Bird { Name =  "Dove", Color = "White", Sightings = 2 },
    new Bird { Name =  "Robin", Color = "Red", Sightings = 5 },
    new Bird { Name =  "Canary", Color = "Yellow", Sightings = 0 }
};

var ourBirds = myBirds.Join(yourBirds,
                            mb => mb.Name,
                            yb => yb.Name,
                            (myBird, yourBird));

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

:point_right: The fourth argument to Join needs to be a function.

Specifically, it needs to be a function to create a result element from two matching elements It should have this signature: Func<TOuter, TInner, TResult>.

Since you're just returning the objects in common, you can write a lambda expression that takes two arguments and returns either one of them:

(myBird, yourBird) => myBird

It kind of looks like you started to do this but just didn't finish.