List of object, get property with separator

Question

public class Person
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

I have a list :

List<Person> list = new List<Person>();

I'd like get, the Id value of all entries of the list with comma separator, like this : id1, id2, id3

Answer 1

Use string.Join to join values and Enumerable.Select to selected desired values:

string allIds = string.Join(", ", list.Select(i => i.Id.ToString()));