java - 尝试输入带有空格的字符串时出现 InputMismatchException

Question

我有一个任务:

5-8)(求最高分)编写一个程序，提示用户输入学生人数以及每个学生的姓名和分数，最后显示分数最高的学生的名字。

当我运行此代码并输入“john”等名称时，它运行良好，但当我尝试输入“John Doe”等名称时，它会抛出 InputMismatchException。我尝试使用 nextLine() 但程序会移动到下一个项目，而无需等待用户输入数据。最后，仍然抛出InputMismatchException错误。截图:ibb.co/ZT2ZhMz

解决方案:我创建了一个新的 Scanner 对象 Scanner inp = new Scanner(System.in).useDelimiter(""); 并用它输入了名称。

package pp;

import java.util.Scanner;

public class BestStudent {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.print("Enter the number of students: ");
        int nos = input.nextInt();

        //Creating arrays to store the inputs
        String []names = new String[nos];
        double []grades = new double[nos];

        //A loop for getting inputs until it reaches number of students(nos) value
        for (int i = 0; i<nos; i++) {
            System.out.println("Student "+(i+1)+" of "+nos);
            System.out.println("Enter student's name: ");
            names[i] = input.next();

            System.out.println("Enter student's score: ");
            grades[i] = input.nextDouble();
        }
        System.out.println("The highest score was:"+highest(grades)+" and "+name(names, grades)+" got it.");


        input.close();
    }
    //A method for finding the highest value
    public static double highest (double []grades) {
        double highest = 0;
        for (int k = 0; k<grades.length; k++) {

            if (grades[k]>highest)
                highest = grades[k];
        }
        return highest;
    }

    //A method for the order of the name that has the highest value.
    public static String name(String []names, double []grades) {
        double highest = 0;
        int order = 0;
        for (int k = 0; k<grades.length; k++) {

            if (grades[k]>highest) {
                highest = grades[k];
                order = k;
            }

        }
        return names[order];

    }

}

Answer 1

发生这种情况是因为标记的默认分隔符是空格。您只需在初始化 Scanner 对象时设置一些配置:

Scanner input = new Scanner(System.in).useDelimiter("\\n");