Merging dictionaries in C#

Question

What\'s the best way to merge 2 or more dictionaries (Dictionary) in C#? (3.0 features like LINQ are fine).

I\'m thinking of a method signa

Answer 1

Note that if you use an extension method called 'Add', you get to use collection initializers to combine as many dictionaries as needed like this:

public static void Add(this Dictionary d, Dictionary other) {
  foreach (var kvp in other)
  {
    if (!d.ContainsKey(kvp.Key))
    {
      d.Add(kvp.Key, kvp.Value);
    }
  }
}


var s0 = new Dictionary {
  { "A", "X"}
};
var s1 = new Dictionary {
  { "A", "X" },
  { "B", "Y" }
};
// Combine as many dictionaries and key pairs as needed
var a = new Dictionary {
  s0, s1, s0, s1, s1, { "C", "Z" }
};