Question

i have tried this code snippet but could not able to figure out the reason for this the exception.

my code is:-

import java.util.*;
class ScannerTest
{
 public static void main(String[]args)
  {
    String csv = "Sue,5,true,3";
    Scanner sc = new Scanner(csv);
    sc.useDelimiter(",");
    int age = sc.nextInt();
    System.out.println(age);
  }
}

Output is:-

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.nextInt(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)

i am new to java so please help me out to know the reason for this exception.

Answer 1

in the javadoc example you can see how it works:

String input = "1 fish 2 fish red fish blue fish";
     Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*");
     System.out.println(s.nextInt());
     System.out.println(s.nextInt());
     System.out.println(s.next());
     System.out.println(s.next());
     s.close(); 

your first token is a string. if you use next int it expects an integer.
you might want to use something like this (under the conditions that you know the structure of the csv and it doesn’t change):

public static void main(String[]args)
      {
        String csv = "Sue,5,true,3";
        Scanner sc = new Scanner(csv);
        sc.useDelimiter(",");
        sc.next();
        int age = sc.nextInt();
        System.out.println(age);
      }

or

public static void main(String[] args) {
        String csv = "Sue,5,true,3";
        String ageString = csv.split(",")[1];
        System.out.println(ageString);
    }

…

to parse a string into int:

int age = Integer.parseInt(ageString);