Question

I have two dictionaries like

Dictionary<String, String> one = new Dictionary<string, string>
{
    { "A", "1" },
    { "B", "2" },
    { "C", "3" },
    { "D", "4" },
    { "E", "5" },
    { "F", "6" },
    { "G", "7" },
    { "H", "8" }
};

Dictionary<String, String> two = new Dictionary<string, string>
{
    { "A", "1" },
    { "B", "2" },
    { "C", "3" },
    { "E", "4" },
    { "F", "4" },
    { "I", "6" },
    { "J", "10" },
    { "K", "11" }
};

i need to merge the two dictionary in key level and then in value level and to add the resulting dictionary into the new dictionary three, the resulting dictionary should not have same keys or same values and in this case the resulting dictionary is like

Dictionary<String, String> three = new Dictionary<string, string>
{
    { "A", "1" },
    { "B", "2" },
    { "C", "3" },
    { "D", "4" },
    { "E", "5" },
    { "F", "6" },
    { "G", "7" },
    { "H", "8" },
    { "J", "10" },
    { "K", "11" }
};

Now i’m using like

1. Union all the keys in the two dictionaries
2. Creating a new dictionary with the new keys
3. removing the dupicate values( same values )

EDIT: if both the dictionaries having same key value pair then i need to store the the key value pair from the first dictionary .

is there any way to do this using LINQ?
Thanks in advance

Answer 1

One option, using the fact that a dictionary is a sequence of key/value pairs:

var dictionary = dictionary1.Concat(dictionary2)
                            .ToLookup(pair => pair.Key, pair => pair.Value)
                            .ToDictionary(x => x.Key, x => x.First());

That’s not terribly efficient, admittedly (as it essentially builds up a hash table twice) but I believe it will work.