Can I compare the keys of two dictionaries?

Question

Using C#, I want to compare two dictionaries to be specific, two dictionaries with the same keys but not same values, I found a method Comparer but I'm not quite sure how can I use it? Is there a way other than iterating through each key?

Dictionary
[
    {key : value}
]

Dictionary1
[
    {key : value2}
]

Answer 1

If all you want to do is see if the keys are different but not know what they are, you can use the SequenceEqual extension method on the Keys property of each dictionary:

Dictionary<string,string> dictionary1;
Dictionary<string,string> dictionary2;
var same = dictionary1.Count == dictionary2.Count && dictionary1.Keys.SequenceEqual(dictionary2.Keys);

If you want the actual differences, something like this:

var keysDictionary1HasThat2DoesNot = dictionary1.Keys.Except(dictionary2.Keys);
var keysDictionary2HasThat1DoesNot = dictionary2.Keys.Except(dictionary1.Keys);

Answer 2

return dict1.Count == dict2.Count && 
       dict1.Keys.All(dict2.ContainsKey);