C#, Lesson 2 of "Xiaobai Learning Programs": Arrays and Sorting

1 text format

/// <summary>
/// Lesson 2 of "Xiaobai Learning Programs": Arrays and Sorting
/// </summary>
/// <param name="sender"></param>
/// <param name ="e"></param>
private void button2_Click(object sender, EventArgs e)
{     // #1 array: a set of data (member or unit)     double[] score = {         540, 340, 650, 120, 554,         643, 612, 234, 345, 456     };     // Number of array members     int n = 10;

    // #2 Print array (sequential output array)
    // Form a long string first, and then output it;
    // StringBuilder is the most commonly used way to combine string data into regular strings;
    StringBuilder sb = new StringBuilder( );
    // AppendLine adds a line; <br> is a newline;
    sb.AppendLine("Score before sorting: <br>");

    // #3 Loop 
    // The sentence (statement) at the beginning of for becomes a loop, which is sequential processing;
    // Detailed explanation of for statement: define a flag i, from 0 to n-1 = (before n); add 1 each time;
    / / Visible array flags (subscripts) start from 0! ! ! ! ! ! !
    #region standard writing
    for (int i = 0; i < n; i++)
    {         sb.AppendLine((i + 1) + ": " + score[i] + "<br>");     }     sb.AppendLine(" <br>");     #endregion

    #region Another way of writing
#if __UNUSED__
    // Detailed explanation of for statement: define a flag i, from 1 to n = (n+1); add 1 each time;
    for (int i = 1; i < n + 1; i++)
    {         sb. AppendLine(i + ": " + score[i - 1] + "<br>");     }     sb. AppendLine("<br>"); #endif     #endregion

    // #4 Sorting
    // Two-layer loop; a starts from the first one, and compares it with every subsequent b's grade;
    // If a's grade exceeds b's grade's exchange;
    for (int i = 0; i < n - 1; i++)
    {         for (int j = i + 1; j < n; j++)         {             if (score[i] > score[j])             {                 // exchange;                 // need a pad (stemp) in the middle For temporary storage of grade a                 double temp = score[i];                 score[i] = score[j];                 score[j] = stemp;             }         }     }

    // #5 Output sorted results
    sb.AppendLine("Scores after sorting from small to large: <br>");
    for (int i = 1; i < n + 1; i++)
    {         sb.AppendLine(i + ": " + score[i - 1] + "<br>");     }     sb. AppendLine("<br>");

    // #6 Output to an exported embedded web browser
    webBrowser1.DocumentText = sb.ToString();
}
 

2 code format

/// <summary>
/// 《小白学程序》第二课：数组与排序
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button2_Click(object sender, EventArgs e)
{
    // #1 数组：一组数据（成员 或 单元）
    double[] score = {
        540, 340, 650, 120, 554,
        643, 612, 234, 345, 456
    };
    // 数组成员的个数
    int n = 10;

    // #2 打印数组（顺序输出数组）
    // 先组成长长的串，最后再输出；
    // StringBuilder 是最常用的进行字符串 数据 组合成常常的字符串的方式；
    StringBuilder sb = new StringBuilder();
    // AppendLine 加一行；<br> 是换行；
    sb.AppendLine("未排序之前的成绩：<br>");

    // #3 循环 
    // for 开始的句子（语句）成为循环，就是顺序处理；
    // for 语句详解：定义一个标志 i, 从 0 到 n-1 = (n之前)；每次加 1 ；
    // 可见数组的标志（下标）是从 0 开始的！！！！！！！
    #region 标准写法
    for (int i = 0; i < n; i++)
    {
        sb.AppendLine((i + 1) + ": " + score[i] + "<br>");
    }
    sb.AppendLine("<br>");
    #endregion

    #region 另一种写法
#if __UNUSED__
    // for 语句详解：定义一个标志 i, 从 1 到 n = (n+1)之前；每次加 1 ；
    for (int i = 1; i < n + 1; i++)
    {
        sb.AppendLine(i + ": " + score[i - 1] + "<br>");
    }
    sb.AppendLine("<br>");
#endif
    #endregion

    // #4 排序
    // 两层循环；a 从第一个开始，每次与后面每一个 b 的成绩比较；
    // 如果 a 成绩超过 b 成绩的交换；
    for (int i = 0; i < n - 1; i++)
    {
        for (int j = i + 1; j < n; j++)
        {
            if (score[i] > score[j])
            {
                // 交换；
                // 中间需要一块垫板(stemp)用于临时存放 a成绩
                double stemp = score[i];
                score[i] = score[j];
                score[j] = stemp;
            }
        }
    }

    // #5 输出排序后的结果
    sb.AppendLine("从小到大排序之后的成绩：<br>");
    for (int i = 1; i < n + 1; i++)
    {
        sb.AppendLine(i + ": " + score[i - 1] + "<br>");
    }
    sb.AppendLine("<br>");

    // #6 输出到一个出口嵌入的网页浏览器
    webBrowser1.DocumentText = sb.ToString();
}

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