C# Case Insensitive Dictionary, Merging dictionaries, Add or Update Dictionary Union

Here is example of merging Case Insensitive dictionaries, thru Linq, Still havent found a way to Union and only get the newest without resorting to a foreach loop....TBC...


After some research, found we can use conditional statement in Liunq ForEach like so to get new or updated dictionary items,

Add or Update Dictionary Union

 kvs2.Keys.ToList().ForEach(x =>
                    {
                        if (kvs.ContainsKey(x))
                        {
                            kvs[x] = kvs2[x];
                        }
                        else
                        {
                            kvs.Add(x, kvs2[x]);
                        }
                    });
                   

C# Case Insensitive Dictionary, Merging dictionaries

  Dictionary<string, string> kvs = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
                kvs.Add("UserID", "Asdasd");
                kvs.Add("Password", "Asdasd");

                Dictionary<string, string> kvs2 = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
                kvs2.Add("userid", "NewUser");
                kvs2.Add("userid2", "Asdasd");
                kvs2.Add("PASSWORD", "NePWD");
                kvs2.Add("PASSWORD2", "Asdasd");


                //var newDict = kvs.Union(kvs2).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => d.First().Value);
                //var newDict = kvs.Union(kvs2).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => (kvs2.ContainsKey(d.Key) ? kvs2[d.key] : d.First().Value));
                var newDict = kvs.Union(kvs2).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => (kvs2.ContainsKey(d.Key) ? kvs2[d.Key] : d.First().Value));
                newDict.Keys.ToList().ForEach(x => Debug.WriteLine(string.Format("Key={0}-> Value={1}", x, newDict[x])));

                var newDict2 = kvs.Concat(kvs2.Where(x => !kvs.Keys.Contains(x.Key))).ToDictionary(d => d.Key, d => d.Value);
                newDict2.Keys.ToList().ForEach(x => Debug.WriteLine(string.Format("Key={0}-> Value={1}", x, newDict[x])));