Using an entire Class as a Parameter - Good practice?

Question

Suppose a class called "Place" stores locations and relevant details:

class Place
{
    string Name;
    string Location;
    // etc...
}

Later on we populate the name and details of up to 80 different towns. So we store these Towns numerically in an array:

class Setup
{
    public static GetTowns
    {
        for (int i = 1; i <= numberOfTowns; i++)
        {
            Town[i] = new Place(name, location);
        }
        // more code...
    }
    // more methods...
}

To access a specific Town and its data, we pass the Town itself as a parameter and receive it:

public static void DescribeTown(Place Town)
{
    // example method from some other class
    Console.WriteLine("Shipping to {0}.", Town.Name);
}

Other methods need access multiple towns, or all of them. Then we can pass in the entire Town array as a parameter:

public static void ListAllTowns(Place[] Town)
{
    Console.WriteLine("Our Beloved Clients:");
    foreach (Place here in Town)
    {
        Console.WriteLine("{0} in {1}", here.Name, here.Location);
        // Various other operations requiring info about the Towns
    }
}

The Complete Reference, C# 2.0, states the following

Parameters are variables that receive the value of the arguments passed into the method when it is called.

This seems to say every instance of a class, and all data involved, is being passed into ListAllTowns each time it is called. That sounds wasteful to me, but is it?

(This example is heavily simplified for proof-of-concept reasons, but methods require read/write permissions and comparison between multiple towns.)

Answer 1

There's nothing wasteful about it. You're not passing a copy of all of the items, you're simply creating an array and then passing a reference to that array to the ListAllTowns method (arrays are reference types).

You're doing things (one of) the right way(s).