Question

我是java的新手，所以请忽略我明显的错误。我有一个txt文件，其格式如下：

Student Name,Mathmatics_Marks,Physics_Marks,Chemistry_Marks,Biology_Marks
A,10,20,30,40
B,15,15,48,69
C,45,48,48,79
D,48,15,12,55

期望输出：

I need to do the following output format from the above txt files:
Student Name (Appended with "Student:" prefix)
Pass/Fail (Appended with "Exam Status:" prefix)
Average_Marks (Appended with "Average_Marks:" prefix)
Maximum_Marks(Appended with "Maximum_Marks:" prefix)
Minimum_Marks(Appended with "Minimum_Marks:" prefix)

For example:
Student: A
Exam Status: Pass
Average_Marks:25
Maximum_Marks:40
Minimum_Marks:10

<<so on for other students>>
...........................
...........................
...........................
...........................

所需输出的逻辑/算法：

1) If (Mathmatics_Marks+Physics_Marks+Chemistry_Marks,Biology_Marks)=>100 then Pass else Fail
2) Find out the average marks of student.
3) Write Maximum marks
4) Write Minimum marks

我的方法： 1-我可以使用以下代码将数据加载到ArrayList并从txt文件打印数据但无法实现所需的输出：

public static void main(String[] args)
    {
        //Input file path
        String fileToParse = "C:\\Users\\DELL-PC\\Desktop\\Analysis.txt";
        BufferedReader fileReader = null;

        //Delimiter Declaration
        final String DELIMITER = ",";
        try
        {
            List<String> Student_log= new ArrayList<String>();
            String line = "";
            //Create the file reader
            fileReader = new BufferedReader(new FileReader(fileToParse));

            //Reading the file line by line
            while ((line = fileReader.readLine()) != null) 
            {
                //Get all tokens available in line
                String[] tokens = line.split(DELIMITER);
                for(String token : tokens)
                {
                    //Print all tokens
                    /// Array Initialization Part 
                    System.out.println(token);
                    Student_log.add(token);
                }
            }
        } 
        catch (Exception e) {
            e.printStackTrace();
        } 
        finally
        {
            try {
                fileReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

请在我的代码中帮助我。

Answer 1

您需要初始化一些变量来计算平均值，最小值，最大值等。然后在while循环中检索每行的值并进行计算。

Example Code:

     while ((line = fileReader.readLine()) != null)  {
                    //Get all tokens available in line
                    String[] tokens = line.split(DELIMITER);
                    name = tokens[0];
                    math = Integer.valueOf(tokens[1]);
                    physics =Integer.valueOf(tokens[2]);
                    chem = Integer.valueOf(tokens[3]);
                    bio = Integer.valueOf(tokens[4]);

                    if (math + physics + chem + bio > 100) {
                        pass = "Pass"; 
                    } else {
                        pass = "Fail";
                    }
                    System.out.println("Student: "+ name);
                    System.out.println("Exam Status: "+ pass);

                }

Answer 2

public static void main(String[] args)
{
    //Input file path
    String fileToParse = "C:\\Users\\DELL-PC\\Desktop\\Analysis.txt";
    BufferedReader fileReader = null;

    //Delimiter Declaration
    final String DELIMITER = ",";
    try
    {
        List<String> Student_log= new ArrayList<String>();
        String line = "";
        //Create the file reader
        fileReader = new BufferedReader(new FileReader(fileToParse));

        //Reading the file line by line
        while ((line = fileReader.readLine()) != null) 
        {
            //Get all tokens available in line
            String[] tokens = line.split(DELIMITER);
            student_log = new ArrayList<>();
            for(String token : tokens)
            {
                //Print all tokens
                /// Array Initialization Part 
                Student_log.add(token);
            }
            // calculate average
            int sum = 0;
            for(int i=1; i<student_log.size();i++){            
            sum = sum + Integer.parseInt(student_log.get(i));            
            }

            double average = sum/(student_log.size()-1);
            String result = "fail";
            if(average > 100){
            result = "pass";
            }
            int max = Integer.parseInt(student_log.get(1));
            //Calculate max
            for(int i=1; i<student_log.size(); i++){
            if(max < Integer.parseInt(student_log.get(i)))
            max = Integer.parseInt(student_log.get(i));
            }
            //Calculate min
            int min = Integer.parseInt(student_log.get(1));
            //Calculate max
            for(int i=1; i<student_log.size(); i++){
            if(min > Integer.parseInt(student_log.get(i)))
            min = Integer.parseInt(student_log.get(i));
            }

            System.out.println("Student: " + student_log.get(0));
            System.out.println("Exam_status: " + result);
            System.out.println("Average marks: " +average);
            System.out.println("Maximum marks: " +max);
            System.out.println("Minimum marks: " +min);
            }
            } 
            catch (Exception e) {
         e.printStackTrace();
    } 
    finally
    {
        try {
            fileReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这样可以正常工作但事实上，您将所有内容存储到字符串的数组列表中。我建议你创建一个类的模型，名称为字符串，所有其他标记为整数。这将是一个很好的编程实践，但是这是一个简单的程序，在这种情况下你可以使用Integer.parseInt（）。

但是，我想在此提出一点意见。计算max和min值时，永远不要为初始max和min变量赋值0。通常很多人这样做。因为，有些情况会出现负面影响（不是在这种情况下）。但是，在这种情况下，如果我们将min指定为0，则永远不会输入循环。

Answer 3

您可能遇到一些问题。首先，您需要一些计算来计算通过/失败，最大值，最小值等。因此，您需要首先遍历这些值以确定，转换为整数，依此类推。然后计算出的值是您要打印出来的值，但是手动添加一些其他文本，而不是在该循环中。所以一些Student_log.add（文字）;声明，每个计算一个。也跳过第一行文字。

Answer 4

您需要忽略第一行并为您的4个选项添加方法，例如

   getAverageMark(List marks) {
     //find average
   }

其中List标记 - 特定学生的所有标记，您必须阅读每行

对ArrayList <string>元素执行字符串追加和算术运算

4 个答案: