Cattle Drive- Assignment 4a

[John Pisci]

Hi Folks,

I'm having a bit of trouble with this exercise. The objective is to run the program with a number, e.g java Say 22 and then get an output of twenty- two (up to a max of 99).

Anyway, 1-9 is working fine for me, but that's it. I can't for the life of me see the problem, so any help would be appreciated! Thanks!

    
Exception in thread "main" java.lang.NumberFormatException: For input string: ""

        at java.lang.NumberFormatException.forInputString(NumberFormatException.
java:48)
        at java.lang.Integer.parseInt(Integer.java:468)
        at java.lang.Integer.parseInt(Integer.java:497)
        at saying.Say.main(Say.java:44)

[* Sorry John, since this is a Cattle Drive assignment we need to keep the code out of the question. -Pauline]

[Campbell Ritchie]

What did you pass as a command-line argument?

[Campbell Ritchie]

And, try passing some Strings to their substring method and see what you get from substring(2) especially when your input String is 2 characters long.

[John Pisci]

Thanks!

Just tried a very simple program (below) and can see where I was going wrong. How can you call the substring() method and only retrieve 1 character?

    
public static void main(String[]args)
  {
    String s = args[0];
    String b = s.substring(1);
    String v = s.substring(2);
    
    System.out.println( "b = "+ b );
    System.out.println( "v = "+ v );
  }

When the input was 'three', the output was:
b = hree
v = ree

[John Pisci]

Fixed it- thanks for your help!

Just changed the following;

    
String b = s.substring(0, 1);
String v = s.substring(1, 2);