nextDouble() don't accept points, just commas

Question

The input is this:

185.50
250.36
163.45
535.20
950.22
450.38
-1

it throws me this:

Exception in thread "main" java.util.InputMismatchException<br>
    at java.base/java.util.Scanner.throwFor(Scanner.java:939)<br>
    at java.base/java.util.Scanner.next(Scanner.java:1594)<br>
    at java.base/java.util.Scanner.nextDouble(Scanner.java:2564)<br>
    at Pruebas.Ventas.main(Ventas.java:25)

but if I input this:

185,50
250,36
163,45
535,20
950,22
450,38
-1

It works perfectly! why?

import java.util.Scanner;

public class Ventas {

    public static void main(String[] args) {


        Scanner scan = new Scanner(System.in);

        double numero = 0;
        double grande = 0;
        double pequeno = 0;
        double suma = 0;
        double media = 0;
        String comprobacion = "";
        int grandePos = 0;
        int pequenoPos = 0;
        String[] semana = {"Martes", "Miercoles", "Jueves", "Viernes", "Sabado", "Domingo"};

        while(numero != -1) {
            double[] dias = new double[6];
            for (int i = 0; i < dias.length; i++) {
                numero = scan.nextDouble(); // This is line 25!
                suma += numero;
                if(numero != -1) {
                    dias[i] = numero;
                    if(numero > grande) {
                        grande = numero;
                        grandePos = i;
                    }else if(pequeno == 0 || numero < pequeno) {
                        pequeno = numero;
                        pequenoPos = i;
                    }
                }else {
                    break;
                }
            }
            media = ((suma - dias[5]) / 5);
            if(media < dias[5]) {
                comprobacion = "NO";
            }else {
                comprobacion = "SI";
            }
        }
        
        System.out.println(semana[grandePos] + " " + semana[pequenoPos] + " " + comprobacion);

        scan.close();
    }

}

Answer 1

Your default locale uses the comma character (,) as the decimal separator, and thus fails parsing inputs with decimal points (.) as doubles. You can override this behavior by explicitly setting a Locale that accepts decimal points. E.g.:

Scanner scan = new Scanner(System.in);
scan.useLocale(Locale.US);