C4 Week10Monday

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" );

-Contains no duplicate elements.

-Can contain at most one Null value.

-Elements are not key-value pairs.

-Accessing an element can be almost as fast as performing a similar operation on an array.

Which of these classes provides the specified features?

• LinkedList

• TreeMap

• HashSet

• LinkedHashMap

• HashMap