How do you use LINQ to find the duplicate of a specific property?

Question

Customer customerOne = new Customer(\"John\", \"Doe\");
Customer customerTwo = new Customer(\"Super\", \"Man\");
Customer customerThree = new Customer(\"Crazy\", \"Guy\"         


        

Answer 1

    var result = from c in customers
                 join c2 in customers on c.LastName equals c2.LastName
                 where c != c2
                 select c;