Java OCA OCP Practice Question 2310

Question

What will be the result of attempting to compile and run the following code? 

class Fruit {}/*from   w w  w  .jav a2  s  .c  o m*/
class Apple extends Fruit {}
class Orange extends Fruit {}

public class Main {
  public static void main(String[] args) {
    ArrayList<Apple> aList = new ArrayList<Apple>();
    aList.add(new Apple());
    ArrayList bList = aList;          // (1)
    ArrayList<Orange> oList = bList;  // (2)
    oList.add(new Orange());
    System.out.println(aList);
  }
}

Select the one correct answer.

  • (a) The code will fail to compile because of errors in (1) and (2).
  • (b) The code will fail to compile because of an error in (1).
  • (c) The code will fail to compile because of an error in (2).
  • (d) The code will compile with an unchecked warning in both (1) and (2).
  • (e) The code will compile with an unchecked warning in (1).
  • (f) The code will compile with an unchecked warning in (2).
  • (g) The code will compile without warnings, but throw a ClassCastException at runtime in (2).
  • (h) The code will compile without warnings and will print "[Apple@hash-code, Orange@hash-code]", when run.


(f)

Note

Assigning bList, a reference of a non-generic list, to oList, a reference of a generic list, in (2) results in an unchecked conversion warning.




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