Beginning C# 3.0

8.5. Collections

A collection is a set of objects that share the same characteristics. You can have a collection of strings, as you do with the weekDays array, or you can have collections of complex objects, like a listview or similar control object.

Try It Out: Squares and Cubes Suppose you wish to iterate through the days and weekDays arrays. Because arrays are objects, you can treat them as a collection. A sample run of a test program is shown in Figure 8-11. Figure 8-11. Figure 8-11 Notice how you can place either collection in the listbox object. How It Works The code for the program is shown in Listing 8-3. Example 8-3. Listing 8-3 using System; using System.Windows.Forms; public class frmMain : Form { private Button btnCalc; private Button btnClose; private ListBox lstTest; #region Windows code public frmMain() { InitializeComponent(); } public static void Main() { frmMain main = new frmMain(); Application.Run(main); } private void btnClose_Click(object sender, EventArgs e) { Close(); } private void btnCalc_Click(object sender, EventArgs e) { int[] days = new int[] { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 31 }; string[] weekDays = new string[] { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"}; foreach (string str in weekDays) { lstTest.Items.Add(str); } foreach (int val in days) { lstTest.Items.Add(val.ToString()); } } } The two arrays ...