ArrayLists and Iterators

10. Summary List Interface


Answer:

0, just as with an array.

    Summary List<E> Interface

    Here is a summary of the List<E> Interface. For the full interface see the Java documentation.

    Method What it Does
    boolean add(E elt)           
    Appends element elt to the end of the list.
    void add(int index, E elt)   
    Inserts element elt at the specified index.
    E remove(int index)          
    Removes the element at the specified index.
    void clear()                 
    Remove all elements, so the list is now empty.
    int indexOf(Object elt)      
    Searches for the first occurrence of elt,
    testing for equality using the equals(Object) method.
    boolean isEmpty()            
    tests if the list is empty
    E set(int index, E elt)      
    Replaces the element at index with the specified element elt.
    . . . many more . . . . . .


    The E in these descriptions means reference to object of type E or of its subclasses. Of course, the List must have been constructed to hold references to that type.


    Question 10:

    Here is a declaration and construction of a ArrayList:

      ArrayList<String> data = new ArrayList<String>(10);

    Which of the following statements will work?

      data.add( "Irene Adler" );
      data.add( new String("Laura Lyons") );
      data.add( 221 );
      data.add( new Integer( 221 ) );