需要从数字列表中显示最高和最低等级

Question

我需要输入成绩列表，并在输入字符时让代码停止。然后它会显示最高等级和最低等级。

我创建了一个while loop，但是当我运行代码时，它一直在循环并且不会停止。

public class MaxMinGrades{
  public static void main(String[] args){
    double maxGrade = Double.MAX_VALUE;
    double minGrade = Double.MIN_VALUE;
    Scanner input = new Scanner(System.in);
    System.out.println("Enter as many student grades as you like. Enter a character to stop.");
    double grades = input.nextDouble();

    while(input.hasNextDouble()) {
      if (grades > maxGrade) {
        maxGrade = grades;
      }
      if (grades < minGrade) {
        minGrade = grades;
      }
    }
    System.out.println("The highest grade is: " + maxGrade);
    System.out.println("The lowest grade is: " + minGrade);
  }
}

我会输入：50 66.85 73.5 78.9 77 q.

输出将是：最高等级是：78.9 最低年级是：50.0

Answer 1

while循环中没有break条件。扫描仪将继续侦听输入。仅当输入非双字符时循环才会退出。

您实际上也没有在每次迭代中获得下一个输入。您需要在循环内调用 input.nextDouble()。

如果你想让它自己退出，你需要添加一个中断条件。例如，您可以在输入一定数量后停止，例如：

int gradeCount = 0;
while(input.hasNextDouble() && gradeCount < 6) {
  grades = input.nextDouble();
  gradeCount += 1;

  // your logic here
}

Answer 2

两点

1。一旦您获得第一个条目，您需要为 Min 和 Max 分配该值。

2。变量等级应使用循环内的最新输入进行更新。

public class MaxMinGrades {
public static void main(String[] args){
    double maxGrade = Double.MAX_VALUE;
    double minGrade = Double.MIN_VALUE;
    Scanner input = new Scanner(System.in);
    System.out.println("Enter as many student grades as you like. Enter a character to stop.");
    double grades = input.nextDouble();

    System.out.println("first entry="+grades);
    minGrade = maxGrade = grades;

    while(input.hasNextDouble()) {
        grades = input.nextDouble();
        if (grades > maxGrade) {
            maxGrade = grades;
        }
        if (grades < minGrade) {
            minGrade = grades;
        }
    }
    System.out.println("The highest grade is: " + maxGrade);
    System.out.println("The lowest grade is: " + minGrade);
}

}

Answer 3

public class MaxMinGrades{
  public static void main(String[] args){
    double maxGrade = 0.0;
            double minGrade = 100.0;
            Scanner input = new Scanner(System.in);
            System.out.println("Enter as many student grades as you like. Enter a character to stop.");


            while(input.hasNextDouble()) {
            double grades = input.nextDouble();
              if (grades > maxGrade) {
                maxGrade = grades;
              }
              if (minGrade > grades) {
                minGrade = grades;
              }
            }
            System.out.println("The highest grade is: " + maxGrade);
            System.out.println("The lowest grade is: " + minGrade);
  }
}

有了这个，while loop 里面就有了中断条件。当某些内容发生变化时，会检查 boolean 条件。

需要从数字列表中显示最高和最低等级

Need to display the Max and Min Grade from a list of numbers

java

loops

max

min

while-loop