Java 扫描器 - 双重错误

Question

我的扫描仪有问题。如果我尝试使用 double，控制台会给出错误消息:

Exception in thread "main" java.util.InputMismatchException at java.util.Scanner.throwFor(Scanner.java:864) at java.util.Scanner.next(Scanner.java:1485) at java.util.Scanner.nextDouble(Scanner.java:2413) at test.test.main(test.java:9)

代码

package test;

import java.util.Scanner;

public class test {
public static void main(String args[]){
    System.out.print("vlozte hmotnost: ");
    Scanner vstup = new Scanner (System.in);
    double hmotnost = vstup.nextDouble();

//------------------------------------------        

    System.out.print("vlozte drahu: ");
    Scanner vstup2 = new Scanner(System.in);
    double draha = vstup2.nextDouble();

//------------------------------------------

    double sila = hmotnost * 10;

//------------------------------------------

    double praca = sila * draha;
    System.out.print("praca je: ");
    System.out.print(praca);
    System.out.println(" Joulov");

Answer 1

输入 1,5 而不是 1.5。另外，如上所述，您可以使用一台扫描仪:

import java.util.Scanner;

public class test {
    public static void main(String args[]) {
        System.out.print("vlozte hmotnost: ");
        Scanner vstup = new Scanner(System.in);
        double hmotnost = vstup.nextDouble();

//------------------------------------------

        System.out.print("vlozte drahu: ");
        double draha = vstup.nextDouble();

//------------------------------------------

        double sila = hmotnost * 10;

//------------------------------------------

        double praca = sila * draha;
        System.out.print("praca je: ");
        System.out.print(praca);
        System.out.println(" Joulov");
    }
}