正在获取错误消息“线程“ main”中的异常” java.util.InputMismatchException”

问题描述 投票:0回答:3
public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int iteam = sc.nextInt();
    Student[] students = new Student[iteam];
    int id;
    String name;
    String city, s_city;
    double marks, s_marks;

    for (int i = 0; i < iteam; i++) {
        id = sc.nextInt();
        name = sc.nextLine();
        city = sc.nextLine();
        marks = sc.nextDouble();
        students[i] = new Student(id, name, city, marks);

    }
}

我收到一个错误“ Exception in thread "main" java.util.InputMismatchException

    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at java.util.Scanner.nextDouble(Unknown Source)"

我也尝试使用next(),但是存在相同的错误。并且我还导入java.util.Scanner。

java java.util.scanner
3个回答
0
投票
当您从一行中读取一个数值,并期望用户点击回车来提交该值时,您必须先消耗行尾,然后才能继续。扫描仪不会自动执行此操作。要让用户输入4个值,每次输入后都按回车键,您的输入循环应如下所示:

for (int i = 0; i < iteam; i++) { id = sc.nextInt(); sc.nextLine(); name = sc.nextLine(); city = sc.nextLine(); marks = sc.nextDouble(); sc.nextLine(); students[i] = new Student(id, name, city, marks); }


0
投票
Scanner#nextLine

完整的示例:

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int iteam = sc.nextInt();
    Student[] students = new Student[iteam];
    int id;
    String name;
    String city, s_city;
    double marks, s_marks;
    for (int i = 0; i < iteam; i++) {
        id = sc.nextInt();
        sc.nextLine();//call next line to prevent exception
        name = sc.nextLine();
        city = sc.nextLine();
        marks = sc.nextDouble();
        students[i] = new Student(id, name, city, marks);
    }
}

0
投票
import java.util.Scanner; public class MyClass { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int iteam = sc.nextInt(); Student[] students = new Student[iteam]; int id; String name; String city, s_city; double marks, s_marks; for (int i = 0; i < iteam; i++) { id = sc.nextInt(); sc.nextLine(); name = sc.nextLine(); city = sc.nextLine(); marks = sc.nextDouble(); students[i] = new Student(id, name, city, marks); } for(Student s: students){ System.out.println(s); } } private static class Student{ private int id; private String name; private String city; private double marks; public Student(int id, String name, String city, double marks){ this.id = id; this.name = name; this.city = city; this.marks = marks; } public String toString(){ return "[Student] Id: "+this.id+", Name: "+this.name+", City: "+this.city+", Mark: "+this.marks; } } }

为您提供一些解释:方法public static void main(String[] args) { Scanner sc = new Scanner(System.in); int iteam; iteam = sc.nextInt(); Student[] students = new Student[iteam]; int id; String name; String city; double marks; for (int i = 0; i < iteam; i++) { id = sc.nextInt(); name = sc.next(); city = sc.next(); marks = sc.nextDouble(); students[i] = new Student(id, name, city, marks); } } next()nextInt()扫描下一个标记作为输入值。但最重要的是Return不算在内,因为您的bash将此视为您的输入。

此外,您的键盘输入是本地解释的,特别是如果您想读取双精度字。例如,英语分隔符写为

DOT,德语写为

COMMA。

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