Question

I’ve a text (file.txt) file . This file is loaded inside a scanner.

In the files there are various lines and in each line there are two doubles and one integer values divided by spaces.

Like this:

1.0 1.2 2
0.9 1.0 10
50.4 9.2 20

I need to fulfill three arrays.

Each array corresponds to a column. Something like:

double[] x = {1.0,0.9,50.4}
double[] y = {1.2,1.0,9.2}
double[] z = {2,10,20}

I tried to to this using this code:

double x[]= new double [3];
double y[]= new double [3];
double z[]= new double [3];

File f = new File(ClassLoader.getSystemResource(file.txt).toURI());
Scanner sc = new Scanner(f);

for (int i=0;j<3;i++){
  x[i] = sc.nextDouble();
  y[i] = sc.nextDouble();
  z[i] = sc.nextDouble();
}

but when the first nextDouble() is executed an “uncaught” (java.util.InputMismatchException) exception.

What am I doing wrong?

Thank you for any hint.

Answer 1

If sc.next() works for you, you need to parse your output as it is of the type String and hence a InputMismatchException.

try:

for (int i=0;j<3;i++) {
  String s;
  s = sc.next();
  x[i] = Double.parseDouble(s);
  s = sc.next();
  y[i] = Double.parseDouble(s);
  s = sc.next();
  z[i] = Double.parseDouble(s);
}