學徒手札

        // Calculate 1 + 2 + ... + N.
        private void calculateButton_Click(object sender, EventArgs e)
        {
            // Get the input number.
            long n = long.Parse(numberTextBox.Text);

            // Calculate the sum.
            long total = 0;
            for (int i = 1; i <= n; i++)
            {
                total += i;
            }

            // Display the result.
            resultTextBox.Text = total.ToString("#,##0");
        }

Fibonacci程式示範For Loop用來計算費波那西數列

        // Calculate the Fibonacci number.
        private void calculateButton_Click(object sender, EventArgs e)
        {
            // Get the input value.
            long n = long.Parse(numberTextBox.Text);

            // Initialize the base cases.
            long fibo1 = 0;    // Initially Fibonacci(0).
            long fibo2 = 1;    // Initially Fibonacci(1).
            long fiboN = 0;    // Initially Fibonacci(0).

            // Calculate the result.
            for (int i = 0; i < n; i++)
            {
                // Calculate fiboN from fibo1 and fibo2.
                fiboN = fibo1 + fibo2;

                // Update fibo1 and fibo2 for the next loop.
                fibo2 = fibo1;
                fibo1 = fiboN;
            }

            resultTextBox.Text = fiboN.ToString("#,##0");
        }

MinMaxAverage程式示範Foreach Loop用來計算所有輸入值的最大最小及平均值

        // Add an item to the list and calculate
        // the minimum, maxiumu, and average.
        private void addButton_Click(object sender, EventArgs e)
        {
            // Add the new number to the list.
            scoresListBox.Items.Add(int.Parse(scoreTextBox.Text));
            scoreTextBox.Clear();
            scoreTextBox.Focus();

            // Find the minimum and maximum,
            // and add up the scores.
            float total = 0;
            int minimum = (int)scoresListBox.Items[0];
            int maximum = (int)scoresListBox.Items[0];
            foreach (int score in scoresListBox.Items)
            {
                total += score;
                if (score < minimum) minimum = score;
                if (score > maximum) maximum = score;
            }

            // Calculate the average.
            float average = total / scoresListBox.Items.Count;

            // Display the results.
            minimumTextBox.Text = minimum.ToString();
            maximumTextBox.Text = maximum.ToString();
            averageTextBox.Text = average.ToString("0.00");
        }

AddOrderItems程式示範巢狀Foreach Loop用來計算所有輸入物品的合計