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Enumeration

It is very common for a program to access the elements of a Vector one by one, in order. This can be done using a counting loop (as has been done so far this chapter); however, an object that implements the Enumeration interface may also be used. To get an Enumeration object for a Vector use this method:

elements()  // Returns an enumeration of the components of the vector.

Once you have an enumeration object, the hasMoreElements() and the nextElement() methods are used to move through the elements:

boolean hasMoreElements()   // return true if not all elements have been visited

Object nextElement()        // Returns the next element of the enumeration. 

Here is a program that prints out every element in the Vector:

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( "Deb" ); 
    names.addElement( "Elaine" ); names.addElement( "Frank" );
    names.addElement( "Gail" );   names.addElement( "Hal" );

    Enumeration enum = names._____________();

    while ( enum._____________() )
      System.out.println(enum._____________()  );

  }
}

Unfortunately, the program is full of blanks.