Combine multiple dictionaries into a single dictionary [duplicate]

Question

Possible Duplicate:
Merging dictionaries in C#

dictionary 1

"a", "1"
"b", "2"

dictionary 2

"c", "3"
"d", "4"

dictionary 3

"e", "5"
"f", "6"

Combined dictionary

"a", "1"
"b", "2"
"c", "3"
"d", "4"
"e", "5"
"f", "6"

How do I combine the above 3 dictionaries into a single combined dictionary?

Answer 1

var d1 = new Dictionary<string, int>(); var d2 = new Dictionary<string, int>(); var d3 = new Dictionary<string, int>();  var result = d1.Union(d2).Union(d3).ToDictionary (k => k.Key, v => v.Value); 

EDIT
To ensure no duplicate keys use:

var result = d1.Concat(d2).Concat(d3).GroupBy(d => d.Key)              .ToDictionary (d => d.Key, d => d.First().Value); 

Answer 2

Just loop through them:

var result = new Dictionary<string, string>();  foreach (var dict in dictionariesToCombine) {     foreach (var item in dict) {         result.Add(item.Key, item.Value);     } } 

(Assumes dictionariesToCombine is some IEnumerable of your dictionaries to combine, say, an array.)