getter方法中的条件语句

Question

对于Java来说相对较新，所以我不知道问题是什么。在此类的getter设置中，我试图评估输入的整数是1、2还是3，然后它将返回此处描述的先前保存的setter之一。我在setter中使用了相同的条件语句，但是getter告诉我，我的方法需要返回int类型。我究竟做错了什么？还是我应该以一种完全不同的方式来做这件事？大声笑。

public class AssignmentMarks {
    private String courseName;
    private int assignment1 = 0, assignment2 = 0, assignment3 = 0;


    public AssignmentMarks(String name, int mark1, int mark2, int mark3){
        //create constructor to use variables.
        this.courseName = name;
        this.assignment1 = mark1;
        this.assignment2 = mark2;
        this.assignment3 = mark3;

    }
    public void setMark(int assignmentNumber, int mark) {
        //assign value of the assignments
        if(assignmentNumber == 1) {
            mark = this.assignment1;
        }else if(assignmentNumber == 2) {
            mark = this.assignment2;
        }else if(assignmentNumber == 3){
            mark = this.assignment3;
        }

    }

    public int getMark(int assignmentNum) {
        if(assignmentNum == 1) {
            return assignment1;
        }else if (assignmentNum == 2) {
            return assignment2;
        } else if (assignmentNum == 3) {
            return assignment3;
        }
    }



}

Answer 1

public int getMark(int assignmentNum) {
    if(assignmentNum == 1) {
        return assignment1;
    }else if (assignmentNum == 2) {
        return assignment2;
    } else if (assignmentNum == 3) {
        return assignment3;
    }

     // in another case       
     throw new Exception("Assignment must be 1, 2 or 3);

}

对于二传手

   public void setMark(int assignmentNumber, int mark) {
            //assign value of the assignments
            if(assignmentNumber == 1) {
                 // BAD mark = this.assignment1; don't set parameter is useless
                 this.assignment1=mark;     
            }else if(assignmentNumber == 2) {
                 // BAD mark = this.assignment2;
                 this.assignment2=mark;     
            }else if(assignmentNumber == 3){
                 // BAD mark = this.assignment3;
                 this.assignment3=mark;
            } 
         // in another case
         throw new Exception("Assignment must be 1, 2 or 3");
}

我不记得您是否必须导入Exception才能抛出它们。如果是，则在代码上方放置import java.lang.Exception。

您的逻辑可以使用数组来改善，但让我们开始吧，在您运行之后...