created: Jan. 06, 2000; revised: 10/05/03, 06/05/06

on ArrayLists and Iterators

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1. Declare and construct an ArrayList with an initial capacity of 20 references to Object.

A.    Object list(20) = new ArrayList() ;
B.    ArrayList list[20] = new ArrayList() ;
C.    ArrayList[Object] list = new ArrayList(20) ;
D.    ArrayList<Object> list = new ArrayList<Object>(20) ;

2. Examine the following code: 

ArrayList<String> list = new ArrayList<String>(10) ;
list.add( "Ann" );
list.add( "Bob" );
list.add( "Eve" );

After the code has exectued, what is the capactiy of list? What is its size?

A.    3, 3
B.    3, 10
C.    10, 3
D.    10, 10

3. Examine the following code: 

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

list.add( "Andy" );
list.add( "Bart" );
list.add( "Carl" );
list.add( 0, "Eve" );

What element will be at index 2 of the list?

A.    Eve
B.    Andy
C.    Bart
D.    carl

4. Examine the following code: 

ArrayList<String> list = new ArrayList<String>() ;

list.add( "Andy" );
list.add( "Bart" );
list.add( "Carl" );
list.add( "Doug" );
list.add( "Elmo" );

Which of the following will replace the element "Carl" with "Zoltan" ?

A.    list[2] = "Zoltan" ;
B.    list.set( "Zoltan", "Carl" );
C.    list.add( "Zoltan", list.indexOf("Carl") );
D.    list.set( list.indexOf("Carl"), "Zoltan" );

5. Examine the following code: 

ArrayList<String> list = new ArrayList<String>() ;

list.add( "Andy" );
list.add( "Bart" );
list.add( "Carl" );
list.add( "Doug" );
list.add( "Elmo" );

Which of the following will change the list so that it looks like: 

Andy
Bart
Carl
Doug
Oscar
Elmo

A.    list.add( 3, "Oscar" ) ;
B.    list.add( 4, "Oscar" ) ;
C.    list.set( 3, "Oscar" ) ;
D.    list.set( 4, "Oscar" ) ;

6. Examine the following code: 

ArrayList<String> list = new ArrayList<String>() ;

list.add( "Andy" );
list.add( "Bart" );
list.add( "Carl" );
list.add( "Doug" );
list.add( "Elmo" );

Which of the following will change the list so that it looks like: 

Andy
Bart
Doug
Elmo

A.    list.remove( 3 );
B.    list.remove( 2 );
C.    list.add( 2, null );
D.    list.set( list.indexOf( "Carl" ), "Doug" );

7. Examine the following code: 

ArrayList<String> list = new ArrayList<String>() ;

list.add( "Andy" );
list.add( "Bart" );
list.add( "Carl" );
list.add( "Doug" );
list.add( "Elmo" );

Which of the following will change the list so that it looks like: 

Andy
Bart
Carl
Doug

A.    list.remove( list.size() );
B.    list.remove( list.size()-1 );
C.    list.remove( 5 );
D.    list.clear( "Elmo" );

8. Examine the following code: 

ArrayList<String> list = new ArrayList<String>() ;

list.add( "Andy" );
list.add( "Bart" );
list.add( "Carl" );
list.add( "Doug" );
list.add( "Elmo" );

Iterator iter = list.___________________;

while( iter.___________ )
  System.out.println( iter.___________ );

Fill in the blanks so that the list is printed.

A.    iterator()       hasNext()     next()
B.    iterator()       next()        nextElement()
C.    elements()       empty()       next()
D.    iterator()       more()        get()

9. What equals() method must you override when defining a class of objects you expect to hold in a ArrayList ?

A.    public boolean equals( Object )
B.    public boolean equals( ArrayList )
C.    boolean equals( Object )
D.    private int equals( Object )

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