K & B example Problem.

[Soumya Ranjan Mohanty]

   import java.util.*;
class ScanIn {
  public static void main(String[] args) {
    System.out.print("input: ");
    System.out.flush();
    try {
      Scanner s = new Scanner(System.in);
      String token;
      do {
        token = s.findInLine(args[0]);
        System.out.println("found " + token);
      } while (token != null);    
    } catch (Exception e) { System.out.println("scan exc"); }
  }
} 

Code is from K&B page no 501. i am not getting the output.

i execute: java ScanIn "\d\d";
input : 12aa675fks
got output as : found null

[sumit kothalikar]

the code compiles fine and i got this as

java ScanIn "\d\d"
input: 12aa675fks

Output :

found 12
found 67
found null

please recompile and check again for your output

[Sahil Kapoor]

Soumya Ranjan Mohanty wrote:

   import java.util.*;
class ScanIn {
  public static void main(String[] args) {
    System.out.print("input: ");
    System.out.flush();
    try {
      Scanner s = new Scanner(System.in);
      String token;
      do {
        token = s.findInLine(args[0]);
        System.out.println("found " + token);
      } while (token != null);    
    } catch (Exception e) { System.out.println("scan exc"); }
  }
} 

I thinkk you are asking that , you are not getting last output ie found = null

The reason is do-while loop , if you use while loop then you would not get the last output.

In do-while loop first token is retrieved and then printed and at last checked against null.