Question: I have an array of Customer[] objects, and I want to use it to create a Dictionary<Customer, string>. What is the easiest way to examine the array for duplicates before I load the Dictionary? I want to avoid "ArgumentException: An item with the same key has already been added". Thanks.

Answer: 
Just call Dictionary.ContainsKey(key) before you add your Customers.
Why not this??

```
Customers.Distinct.ToDictionary(o=>o, GenerateString(o));

```