linq foreach item in list with more than one matching element

Question

I have a list of cars. Each car has a number of doors. And each door has a color. I want to iterate over the list and select only those cars that have more than one door of a matching color.

I've tried something like this but it's not working like I expect it to:

foreach (Car car in cars.Where(c=>c.doors.Select(d=>d.color = "Blue").Count() > 1))
{
     // Do something     
}

Can you help me understand what I'm doing wrong?

Answer 1

You use c.color = "blue" which is assignment. you should use c.color == "blue" or color.Equals("blue") for comparison.

Answer 2

You need to replace Select with Where and pass a predicate:

foreach (Car car in cars.Where(c=>c.doors.Where(d=>d.color == "Blue").Count() > 1))

To make it shorter:

foreach (Car car in cars.Where(c=>c.doors.Count(d=>d.color == "Blue") > 1))