有没有更简单的方法来执行if语句？

Question

我正在开发一个java程序，它接受输入的分数，给出输入的总数和平均值，但是我很难计算出如何获得当前输入的最高分数“我使用了大量嵌套的else-if语句，但必须有一种简单的方法来实现这一点，而不是键入100个else-if语句这是我的代码。我在else-if语句开始的地方添加了一条注释，以确定最高级别

//Jonathan Towell
//This program will take grade inputs and then display the amount of A's B's C's D's and F's
import javax.swing.JOptionPane;


public class Grades 
{
public static void main(String[] args)
{
    JOptionPane.showMessageDialog(null, "Welcome to Jonathan's Gradebook");
    int A = 0, B = 0, C = 0, D = 0, F = 0;
    int totalGrades = 0, grade = 0, averageGrade = 0, highestGrade = 0;
    while (grade >= 0)
    {
    grade = Integer.parseInt(JOptionPane.showInputDialog("Enter one grade followed by the enter key\n when finished enter -1"));
    if (grade <= 100 && grade >= 90)
    {
        A = A + 1;
        totalGrades = totalGrades + 1;
        averageGrade = averageGrade + grade;
        if (grade == 100) // Determines highest grade
        {
            highestGrade = 100;
        }
        else if (grade == 99)
        {
            highestGrade = 99;
        }
        else if (grade == 98)
        {
            highestGrade = 98;
        }
        else if (grade == 97)
        {
            highestGrade = 97;
        }
        else if (grade == 96)
        {
            highestGrade = 96;
        }
        else if (grade == 95)
        {
            highestGrade = 95;
        }
        else if (grade == 94);
        {
            highestGrade = 94;
        }
    }

    else if (grade > 100)
    {
        JOptionPane.showMessageDialog(null, "No extra credit for this assignment\n please enter a value less than 100");
    }
    else if (grade <= 89 && grade >= 80)
    {
        B = B + 1;
        totalGrades = totalGrades + 1;
        averageGrade = averageGrade + grade;
    }
    else if (grade <= 79 && grade >= 70)
    {
        C = C + 1;
        totalGrades = totalGrades + 1;
        averageGrade = averageGrade + grade;
    }
    else if (grade <= 69 && grade >= 60)
    {
        D = D + 1;
        totalGrades = totalGrades + 1;
        averageGrade = averageGrade + grade;
    }
    else if (grade <= 59 && grade >= 0)
    {
        F = F + 1;
        totalGrades = totalGrades + 1;
        averageGrade = averageGrade + grade;
    }
    }
    averageGrade = (averageGrade / totalGrades);
    JOptionPane.showMessageDialog(null, "Total number of grades entered was " + totalGrades + "\n The average grade was: " + averageGrade + " percent." + "\nA's: " + A + "\nB's: " + B + "\nC's: " + C + "\nD's: " + D + "\nF's: " + F + "\nThe highest grade earned was: " + highestGrade + " percent.");
    System.exit(0);
}


}

Answer 1

乔纳森，

你重复了很多代码。在每个if子句中，重复相同的两行代码。为什么不把这两行代码放在if子句之外呢。这两行重复：totalGrades=totalGrades 1；averageGrade=averageGrade品位；

关于if的巨大if语句（等级==100）//确定最高等级{

将其替换为：等级=（等级

您还可以使用：Highest等级=Math.max（Highest等级，等级）；

我还重新排序了部分代码。你的if语句说“如果在100到90之间”，然后变成“如果在100以上”。这太令人困惑了。我把它排序为“如果在100以上”，然后是“如果在100到90之间”，这更合乎逻辑。

最终代码应如下所示：

public class Grades 
{
    public static void main(String[] args)
    {
        JOptionPane.showMessageDialog(null, "Welcome to Jonathan's Gradebook");
        int A = 0, B = 0, C = 0, D = 0, F = 0;
        int totalGrades = 0, grade = 0, averageGrade = 0, highestGrade = 0;
        while (grade >= 0)
        {
        grade = Integer.parseInt(JOptionPane.showInputDialog("Enter one grade followed by the enter key\n when finished enter -1"));
        if (grade > 100) {
            JOptionPane.showMessageDialog(null, "No extra credit for this assignment\n please enter a value less than 100");
        } else if (grade <= 100 && grade >= 90) {
            A = A + 1;
            grade = (grade > highestGrade ? highestGrade : grade);// Determines highest grade
        } else if (grade <= 89 && grade >= 80) {
            B = B + 1;
        } else if (grade <= 79 && grade >= 70) {
            C = C + 1;
        } else if (grade <= 69 && grade >= 60) {
            D = D + 1;
        }  else if (grade <= 59 && grade >= 0) {
            F = F + 1;
        }
        totalGrades = totalGrades + 1;
        averageGrade = averageGrade + grade;
        averageGrade = (averageGrade / totalGrades);
        JOptionPane.showMessageDialog(null, "Total number of grades entered was " + totalGrades + "\n The average grade was: " + averageGrade + " percent." + "\nA's: " + A + "\nB's: " + B + "\nC's: " + C + "\nD's: " + D + "\nF's: " + F + "\nThe highest grade earned was: " + highestGrade + " percent.");
        System.exit(0);
    }

}

让我知道这是否对你更好。

Answer 2

为了使其更易于管理，您可以考虑使用具有多态性的工厂模式，并在其自己的单独类中实现所有等级括号（if，else if）。