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.txt 文件如下所示：

Gator Ali 85
Vator Ella 75
Beam James 95
Lastin Class 55

我见过其他人试图在这里获得类似的代码，但这些都没有帮助。
我可以得到平均值；但是，如果分数低于平均水平 10 分，我还需要打印出来。
这是我的输出：运行：

欢迎来到学生成绩申请表。

Ali Gator 85
Ella Vator 75
James Beam 95
Class Lastin 55
Beam, James: 95
Gator, Ali: 85
Lastin, Class: 55
Vator, Ella: 75

Your score is 10 points or more below the class average

Class Average: 77.5

这是我的代码： 

public static void main(String[] args) throws Exception {

    Scanner aScanner = new Scanner(new FileReader("src//chapt11//Studentdata.txt"));
    System.out.println("Welcome to the Student Scores Application.\n");

    int nStudent = 100;
    Student[] studentArray = new Student[nStudent];
    int counter = 0;
    while (aScanner.hasNext()) {
        String lastName = aScanner.next();
        String firstName = aScanner.next();
        int score = aScanner.nextInt();
        System.out.println(firstName + " " + lastName + " " + score);
        studentArray[counter++] = new Student(lastName, firstName, score);  
        Arrays.sort(studentArray, 0, counter); 
    } 

    System.out.println();

    for(int j = 0; j < counter; j++){  
        System.out.println(studentArray[j]);
    }

    double sum = 0;
    for(int j = 0; j < counter; j++){    
        sum += studentArray[j].getExamScore();
    }
    double average = (sum*1.0)/counter;

    for(int j = 0; j < counter; j++){    
        int score = studentArray[j].getExamScore();
        if (score <= (average - 10)){
             System.out.println("Your score is 10 points or more below the class average");
        } 
    }
    System.out.println();
    System.out.println("Class Average: " + average);

    System.out.println();
    aScanner.close();  
}

class Student implements Comparable<Student> {
private String firstName;
private String lastName;
private int score;

public Student(String firstName, String lastName, int score) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.score = score;
}

public int getExamScore() {
    return score;
}

public String getFirstName() {
    return firstName;
}

public String getLastName() {
    return lastName;
}

@Override
public int compareTo(Student s) {
    if(!firstName.equalsIgnoreCase( s.firstName)) {
        return firstName.compareToIgnoreCase(s.firstName);
    }
    if(!lastName.equalsIgnoreCase(s.lastName)) {
        return lastName.compareToIgnoreCase(s.lastName);
    }
        return score - s.score;
    }
 @Override 
 public String toString(){ 
        return firstName + ", " + lastName + ": "+ score;
    }
}
4

1 回答 1

1

我发现您的代码存在一些问题。

首先，Arrays.sort每次添加 aStudent到studentArray. 将此方法调用放在while排序完整数组的末尾之外，只需一次调用该方法。

其次，更重要的是，您希望如何Student比较对象？

里面的compareTo方法Student没有意义。如果您希望学生仅按他们的分数排序，您应该有这样的东西：

@Override
public int compareTo(Student s) {
    return this.score - s.score;
}

就预期输出而言，这就是正在发生的事情。

以下行在Student将它们添加到数组时打印它们：

System.out.println(firstName + " " + lastName + " " + score);

这部分再次打印每个Student对象：

for (int j = 0; j < counter; j++) {
    System.out.println(studentArray[j]);
}

并且仅当score <= (average - 10)评估为 true时才会打印此行：

System.out.println("Your score is 10 points or more below the class average");

我相信你现在看到了问题。

于 2013-03-03T23:20:50.010 回答