B4 - ArrayLists and Iterators

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

• Object list(20) = new ArrayList() ;

• ArrayList list[20] = new ArrayList() ;

• ArrayList[Object] list = new ArrayList(20) ;

• ArrayList<Object> list = new ArrayList<Object>(20) ;

Examine the following code:

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

list.add( "Ann" );

list.add( "Bob" );

list.add( "Eve" );

After the code has executed, what is the capacity of list? What is its size?

• 3, 3

• 3, 10

• 10, 3

• 10, 10

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?

• Eve

• Andy

• Bart

• carl

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" ?

• list[2] = "Zoltan" ;

• list.set( "Zoltan", "Carl" );

• list.add( "Zoltan", list.indexOf("Carl") );

• list.set( list.indexOf("Carl"), "Zoltan" );

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

• list.add( 3, "Oscar" ) ;

• list.add( 4, "Oscar" ) ;

• list.set( 3, "Oscar" ) ;

• list.set( 4, "Oscar" ) ;

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

• list.remove( 3 );

• list.remove( 2 );

• list.add( 2, null );

• list.set( list.indexOf( "Carl" ), "Doug" );

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

• list.remove( list.size() );

• list.remove( list.size()-1 );

• list.remove( 5 );

• list.clear( "Elmo" );

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.

• iterator() hasNext() next()

• iterator() next() nextElement()

• elements() empty() next()

• iterator() more() get()

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" );

while( ________ name : ___________ )

System.out.println( ___________ );

Fill in the blanks so that the list is printed.

• String list name

• String iterator() next()

• int String name

• iterator() String list

Which of the following declarations would be appropriate for a list that is expected to contain integers?

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

• ArrayList<int> list = new ArrayList<int>() ;

• ArrayList<Integer> list = new ArrayList<Integer>() ;

• ArrayList list = new ArrayList() ;