Collections and repeated work

15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.

A collection stores related values. The loop visits 1, 2, and 3, updating the total from 0 to 1, then 3, then 6. Record this trace rather than guessing. Identify the first and last valid positions in this language: Pascal can declare a 1-based array, while many other examples use zero-based containers. Add another value and update the bounds correctly. Explain what an empty collection should produce.

Main is the entry method inside Program. Console.WriteLine prints a line. A class instance can have several references to the same object; assigning a reference does not clone the object.

using System;
using System.Collections.Generic;
class Program {

    static void Main() {
        int[] minutes = {1, 2, 3};
        int total = 0;
        foreach (int value in minutes) total += value;
        Console.WriteLine(total);
    }
}

Expected result: 6

Practice and evidence

Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.

Language reference