A good answer might be:

Linear Search

Searching for an Element

Linear search is starting at the first element and examining them one by one until the target element is found. You could write linear search for a Vector (and it would be a good exercise to do so); but there is a method that does this for you: 

int indexOf(Object elem)    //  Search for the first occurrence of 
                            //  elem, testing for equality 
                            //  using the equals method of elem.
The method returns the index of the first occurrence of elem or -1 if elem is not found.

QUESTION 15:

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.addElement( "Deb" );
    names.addElement( "Chris" );  names.addElement( "Joe" );

     System.out.println( names.indexOf( "Bob" ) ); 
     System.out.println( names.indexOf( "Elaine" ) ); 
  }
}

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