How to make IEnumerable readonly?

Question

Why are the lists list1Instance and p in the Main method of the below code pointing to the same collection?

class Person
         


        

Answer 1

Return a new instance of Person that is a copy of p instead of p itself in Get(). You'll need a method to make a deep-copy of a Person object to do this. This won't make them read only, but they will be different than those in the original list.

public IEnumerable Get()
{
    foreach (Person p in l1)
    {
        yield return p.Clone();
    }
}