Question

我试图通过我知道的方式解决这个问题，但我现在还没有任何线索，而且我的教授是一个完全的工具，如果你甚至寻求帮助就会贬低你，请帮忙。这是我要通过课程所要做的项目之一。

public class Student {
    private String name;           //name of the student
    private String id;             //student id
    private String major;          //student’s major: CSCI,MATH,NURS, all others are XXXX
    private int    completedHours; //number of hours the student has completed
    private int    qualityPoints;  //number of overall quality points a student has completed
    private char   studentType;    //type of student G (graduate) U (undergraduate) X (invalid type)

    public Student() {

    }

    public Student(String name) {
        setName(name);
    }//end Student()

    public Student(String name, String id, String major, char studentType) {
        setName(name);
        setId(id);
        setMajor(major);
        setStudentType(studentType);
    }//end Student(String,String,String,char)

    public void setName(String Name) {
        this.name = name;
    } //end setName(String)

    public void setId(String id) {
        this.id = id;
    }//end setId(String)

    public void setMajor(String major) {
        this.major = major;
    }//end setMajor(String)

    public void setCompletedHours(int hours) {
    hours = completedHours;
    }//end setCompletedHours(int)

    public void setQualityPoints(int points) {
        points = qualityPoints;
    }//end setQualityPoints(int)

    public void setStudentType(char type) {
        if (type == 'u' && type == 'U')
            type = 'U';
        else if (type == 'g' && type == 'G')
            type = 'G';
        else 
            type = 'X';

        type = studentType;
    }//end setStudentType(char)

    public String getName() {
        return name;
    }//end getStudentName()

    public String getId() {
        return id;
    }//end getId()

    public String getMajor() {
        return major;
    }//end getMajor()

    public int getCompletedHours() {
        return completedHours;
    }//end getCompletedHours()

    public int getQualityPoints() {
        return qualityPoints;
    }//end getQualityPoints()

    public char getStudentType() {
        return studentType;
    }//end 

    public double gpa() {
        double gpa;

        gpa = qualityPoints / completedHours;

        return gpa;
    }

    public void addCompletedHours(int hours) {
        if ( hours<0) {
            completedHours = completedHours;
        } else {
            if (hours >=0)
                completedHours += hours;
        }
    }

    public String classification() {
        String strClassification;
        strClassification = "A";

        if (studentType == 'G')
            strClassification = "Graduate";
        else if (studentType == 'X')
            strClassification = "Invalid Student Type";
        else if (completedHours<30)
            strClassification = "Freshman";
        else if (completedHours<60)
            strClassification = "Sophomore";
        else if (completedHours<90)
            strClassification = "Junior";
        else if (completedHours>90)
            strClassification = "Senior";

        return strClassification;
    }

    public String studentRecord() {
        String  strStudentRecord;
        strStudentRecord = ("\n Name:\t\t" + name + "\n ID:\t\t\t"  + id + "\nMajor:\t\t" + major + "\nCompletedHrs: " + completedHours + "\nQuality Pts:\t" + qualityPoints + "\nGPA:\t\t\t" + gpa() + "\nClassification:   " + classification());

        return strStudentRecord;
    }

}

例外：

Execption in thread "main" java.lang.ArithmeticEcxeption: / by zero
at Student.gpa(Student.java:105)
at Student.studentRecord(Student.java:164)
at Project3.main(Project3.java:11)

班级项目3：

public class Project3 {

    public static void main(String[] args) {
        String strStudent1;

        Student stu1 = new Student("John Smith", "1234B", "Nursing", 'U');
        stu1.setCompletedHours(34);
        stu1.setQualityPoints(85);

        strStudent1 = stu1.studentRecord();

        System.out.print(strStudent1);
    }//end main
}//end Project3

Answer 1

你的二传手错了。

此：

public void setCompletedHours(int hours)
{
    hours = completedHours;
}//end setCompletedHours(int)

public void setQualityPoints(int points)
{
    points = qualityPoints;

}//end setQualityPoints(int)

应该是这样的：

public void setCompletedHours(int hours)
{
    completedHours = hours;
}//end setCompletedHours(int)

public void setQualityPoints(int points)
{
    qualityPoints = points;

}//end setQualityPoints(int)

您没有在您的二传手中设置任何内容。因此，qualityPoints和completedHours都为零。

然后，当你致电gpa()时，它会尝试除以零。顺便说一句，下次尝试调试它，你应该看到你的价值观。

无法在Java中修复/零错误

1 个答案: