Java Questions Repository

Which statements about polymorphism and method inheritance are correct? (Choose all that apply.)

 
A. Given an arbitrary instance of a class, it cannot be determined until runtime which overridden method will be executed in a parent class. 

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B. It cannot be determined until runtime which hidden method will be executed in a parent class. 

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C. Marking a method static prevents it from being overridden or hidden. 

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D. Marking a method final prevents it from being overridden or hidden. 

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E. The reference type of the variable determines which overridden method will be called at runtime. 

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F. The reference type of the variable determines which hidden method will be called at runtime.

In this code:

public class Deer { 
    enum Food {APPLES, BERRIES, GRASS} 
     protected class Diet { 
          private Food getFavorite() { 
                return Food.BERRIES; 
          } 
 } 
 public static void main(String[] seasons) { 
     System.out.print(switch(new Diet().getFavorite()) { 
     case APPLES -> "a"; 
     case BERRIES -> "b"; 
     default -> "c"; 
      }); 
 } }

In this code:

1: public interface Omnivore { 
2:    int amount = 10; 
3:    static boolean gather = true; 
4:    static void eatGrass() {} 
5:    int findMore() { return 2; } 
6:    default float rest() { return 2; } 
7:    protected int chew() { return 13; } 
8:    private static void eatLeaves() {} 
9: }

In this code:

1: public class Ostrich { 
2:     private int count; 
3:     static class OstrichWrangler { 
4:           public int stampede() { 
5:                    return count; 
6:            } } }

In this code:

public class Ghost { 
    public static void boo() { 
        System.out.println("Not scared"); 
    } 
    protected final class Spirit { 
        public void boo() { 
               System.out.println("Booo!!!"); 
        } 
    }
    public static void main(String... haunt) { 
               var g = new Ghost().new Spirit() {}; 
               ------------------------------------------------------; 
    } 
}

in this code:

public class Weather { 
    enum Seasons { 
        WINTER, SPRING, SUMMER, FALL 
    }
public static void main(String[] args) { 
     Seasons v = null; 
     switch (v) { 
          case Seasons.SPRING -> System.out.print("s"); 
          case Seasons.WINTER -> System.out.print("w"); 
          case Seasons.SUMMER -> System.out.print("m"); 
          default -> System.out.println("missing data"); } 
      } 
}