data structures - How do you clone a dictionary in .NET?

Question

I know that we should rather be using dictionaries as opposed to hashtables. I cannot find a way to clone the dictionary though. Even if casting it to ICollection which I do to get the SyncRoot, which I know is also frowned upon.

I am busy changing that now. Am I under the correct assumption that there is no way to implement any sort of cloning in a generic way which is why clone is not supported for dictionary?

question from:https://stackoverflow.com/questions/2279619/how-do-you-clone-a-dictionary-in-net

Answer 1

Use the Constructor that takes a Dictionary. See this example

var dict = new Dictionary<string, string>();

dict.Add("SO", "StackOverflow");

var secondDict = new Dictionary<string, string>(dict);

dict = null;

Console.WriteLine(secondDict["SO"]);

And just for fun.. You can use LINQ! Which is a bit more Generic approach.

var secondDict = (from x in dict
                  select x).ToDictionary(x => x.Key, x => x.Value);

Edit

This should work well with Reference Types, I tried the following:

internal class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public User Parent { get; set; }
}

And the modified code from above

var dict = new Dictionary<string, User>();

dict.Add("First", new User 
    { Id = 1, Name = "Filip Ekberg", Parent = null });

dict.Add("Second", new User 
    { Id = 2, Name = "Test test", Parent = dict["First"] });

var secondDict = (from x in dict
                  select x).ToDictionary(x => x.Key, x => x.Value);

dict.Clear();

dict = null;

Console.WriteLine(secondDict["First"].Name);

Which outputs "Filip Ekberg".