Collections

Identify examples of autoboxing. Please select 3 options.

• Float f = 2.0;

• Float f = 2.0f;

• Byte b = 2;

• Character c = 2;

• String s = "x";

Identify examples of auto-unboxing. Please select 2 options.

• int getValue(){ return new int[]{ 1 }; }

• new ArrayList<Integer>().add(1);

• List<Integer>.of(1, 2, 3 );

• int ival = optionalInt.get(); //assuming optionalInt is of type Optional<Integer>

• long lv = Integer.valueOf(10);

Which interfaces does java.util.NavigableMap extend directly or indirectly? . Please select 2 options.

• java.util.SortedSet

• java.util.Map

• java.util.SortedMap

• java.util.TreeMap

• java.util.List

Please select 1 option.

• 1

• 2

• 3

• 4

• None of these

Please select 1 option.

• [b]

• [c]

• [b, c, a]

• [a, b, c, a]

• Exception at runtime

Which of these implementations for collection framework interfaces are provided in the standard JDK?. Please select 3 options.

• TreeMap

• ArrayMap

• HashSet

• ArrayList

Please select 1 option.

• ArrayList<Vehicle> al1 = new ArrayList<>();
  al1.add(new SUV());

• ArrayList<Drivable> al2 = new ArrayList<>();
  al2.add(new Car());

• ArrayList<Drivable> al3 = new ArrayList<>();
  al3.add(new SUV());

• ArrayList<SUV> al4 = new ArrayList<>();
  al4.add(new Car());

• ArrayList<Vehicle> al5 = new ArrayList<>();
  al5.add(new Car());

Code that uses generic collection classes can interoperate with code that uses raw collections classes because of?. Please select 1 option.

• type erasure

• reification

• just in time compilation

• byte code instrumentation

Which of these interfaces are in the Java Collections framework? . Please select 4 options.

• Set

• Union

• NavigableMap

• Collection

• Map

Identify the concrete classes that can be used to store key - value pairs? . Please select 2 options.

• java.util.HashMap

• java.util.Set

• java.util.SortedSet

• java.util.Map

• java.util.TreeMap