Can't change struct's members value inside generic collections

Question

Imagine this struct :

        struct Person
        {
             public string FirstName { get; set; }
             public string LastName { g         


        

Answer 1

Redo your struct as such:

    struct Person
    {
         private readonly string firstName;
         private readonly string lastName;
         public Person(string firstName, string lastName)
         {
             this.firstName = firstName;
             this.lastName = lastName;
         }
         public string FirstName { get { return this.firstName; } }
         public string LastName { get { return this.lastName; } }
    }

And following code as :

    var list = new List();
    list.Add(new Person("F1", "L1"));
    list.Add(new Person("F2", "L2"));
    list.Add(new Person("F3", "L3"));

    // Can modify the expression because it's a new instance
    list[1] = new Person("F22", list[1].LastName);

This is due to the copy semantics of struct. Make it immutable and work within those constraints and the problem goes away.