In C# how do I get a list of the keys from a dictionary?

Question

I have the following code: ``` Dictionary inventory; // this is passed in as a parameter. It is a map of name to price // I want to get a list of the keys. // I THOUGHT I could just do: List inventoryList = inventory.Keys.ToList(); ``` But I get the following error: 'System.Collections.Generic.Dictionary.KeyCollection' does not contain a definition for 'ToList' and no extension method 'ToList' accepting a first argument of type 'System.Collections.Generic.Dictionary.KeyCollection' could be found (are you missing a using directive or an assembly reference?) Am I missing a using directive? Is there something other than ``` using System.Collections.Generic; ``` that I need? EDIT ``` List < string> inventoryList = new List(inventory.Keys); ``` works, but just got a comment regarding LINQ

Accepted Answer

You can either use the `Enumerable.ToList` extension method, in which case you need to add the following: ``` using System.Linq; ``` Or you can use a different constructor of `List`, in which case you don't need a new `using` statement and can do this: ``` List inventoryList = new List(inventory.Keys); ```

In C# how do I get a list of the keys from a dictionary?

Solution

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