Inner and Nested Classes: Nested 1

/**
 *  This code is from the book:
 *    Winder, R and Roberts, G (1998)
 *    Developing Java Software
 *    John Wiley & Sons.
 *  It is copyright (c) 1997 Russel Winder
 *  and Graham Roberts.
 */

import java.util.Vector;

class l1Nest2{//Class3
  private Vector items = new Vector();

  static private class CountedString{
    public CountedString(String s){
      item = s;
    }
    String item;
    int count = 1;
  }

  //If the String argument already exists,
  //increment the count. Otherwise add a 
  //new CountedString with a count of 1
  public void addString(String s){
    CountedString tmp = searchFor(s);
    if (tmp == null){
      items.addElement(new CountedString(s));
    }
    else{
      tmp.count++;
    }
  }

  //Return the number of times a string has been added
  public int getCount(String s){
    CountedString tmp = searchFor(s);
    return tmp == null ? 0 : tmp.count;
  }

  //If a string has already been added,
  //return its CountedString
  //object, otherwise return null.
  private CountedString searchFor(String s){
    for (int i = 0; i < items.size(); i++){
      CountedString tmp = 
		(CountedString)items.elementAt(i);
      if ((tmp.item).equals(s))
        return tmp;
    }
    return null;
  }

  public static void main(String[] args){
    l1Nest2 c3 = new l1Nest2();
    c3.addString("hello");
    c3.addString("world");
    c3.addString("world");
    c3.addString("hello");
    c3.addString("hello");
    c3.addString("world");
    c3.addString("hello");
    c3.addString("world");
    c3.addString("hello");
    c3.addString("hello");
    c3.addString("world");
    c3.addString("world");

    System.out.println("hello as been added " +
              c3.getCount("hello") + " times");
    System.out.println("world as been added " +
              c3.getCount("world") + " times");
    System.out.println("Hello as been added " +
              c3.getCount("Hello") + " times");
  }
}
/******** sample compilation & run *******
# javac l1Nest2.java 
# java l1Nest2  
hello as been added 6 times
world as been added 6 times
Hello as been added 0 times
# 
******************************************/