The compete program is below.
The counting loop uses the size() method to ensure that every
element is accessed.
A Vector has data in slots 0 to
size()-1.
import java.util.* ;
class VectorEg
{
  public static void main ( String[] args)
  {
    Vector names = new Vector( 10 );
    names.addElement( "Amy" );
    names.addElement( "Bob" );
    names.addElement( "Chris" );
    names.addElement( "Dan" );
    names.addElement( "Elaine" );
    names.addElement( "Fred" );
    for ( int j=0; j < names.size(); j++ )
      System.out.println( j + ": " + names.elementAt(j) ); 
  }
}
In most programs,
the size of the Vector
changes as the program executes.
For bug-free code, use size() so that the 
loop always works.
Examine the following program. What will it print?
import java.util.* ;
class VectorEg
{
  public static void main ( String[] args)
  {
    Vector names = new Vector( 10 );
    names.addElement( "Amy" );
    names.addElement( "Bob" );
    names.addElement( "Chris" );
    names.setElementAt( "Zoe", 0 );
    names.setElementAt( "Bart", 1 );
    for ( int j=0; j < names.size(); j++ )
      System.out.println( j + ": " + names.elementAt(j) ); 
  }
}