C# – Efficiently merge string arrays in .NET, keeping distinct values


I'm using .NET 3.5. I have two string arrays, which may share one or more values:

string[] list1 = new string[] { "apple", "orange", "banana" };
string[] list2 = new string[] { "banana", "pear", "grape" };

I'd like a way to merge them into one array with no duplicate values:

{ "apple", "orange", "banana", "pear", "grape" }

I can do this with LINQ:

string[] result = list1.Concat(list2).Distinct().ToArray();

but I imagine that's not very efficient for large arrays.

Is there a better way?

Best Solution

string[] result = list1.Union(list2).ToArray();

from msdn: "This method excludes duplicates from the return set. This is different behavior to the Concat(TSource) method, which returns all the elements in the input sequences including duplicates."