Quick Tip: Using LINQ to convert from List to Dictionary

Ever need to easily access a collection of items by their key?  Exactly, you use a Dictionary!

But how do you easily convert a List to a Dictionary? Just use a little LINQ. Let’s say you have a simple class:

public class Stuff
{
    public int Key { get; set; }

    public Stuff(int key)
    {
        Key = key;
    }
}

Here is how you can take a List of Stuff and convert it into a Dictionary with the Key property as the accessor:

var listofStuff = new List
{
    new Stuff(1),
    new Stuff(2),
    new Stuff(3)
};

var dictionaryOfStuff = listofStuff.ToDictionary(s => s.Key);

No you can access the Stuff objects by their key!

var stuff1 = dictionaryOfStuff[1];
var stuff2 = dictionaryOfStuff[2];
var stuff3 = dictionaryOfStuff[3];

Nice and easy!