Lambdas e Interfaces Funcionales 2

Which of the following expressions can be used to implement a Function<Integer, String> ?. Please select 3 options

• (a)-> Integer.toHexString(a)

• a -> Integer::toHexString

• Integer::toHexString

• i::toHexString
  (Assume that i is a reference to an Integer object.)

• (Integer a)-> Integer.toHexString(a)

Please select 1 option.

• Compilation error at //1

• Compilation error at //2

• 15

• -15

• 20

Please select 3 options.

• process(fnames, t::eat);

• process(fnames, t::calories);

• process(fnames, TestClass::size);

• process(fnames, Carnivore::calories);

• process(fnames, Tiger::eat);

Which of the following interface definitions can be implemented using lambda expressions?. Please select 1 option.

• interface A{

  }

• @FunctionalInterface

  interface A{

  default void m(){};

  }

• interface A{

  void m(){};

  }

• interface A{

  default void m1(){};

  void m2();

  }

• @FunctionalInterface

  interface A{

  void m1();

  void m2();

  }

Which of the following is/are a valid functional interface(s)?. Please select 3 options.

• @FunctionalInterface
  public interface FI{
     int m1();
     boolean equals(Object o);
  }

• @FunctionalInterface
  public interface FI{
     String toString = "VALUE";
     int m1();
     String m2(String s);
  }

• public interface FI{
     int m1();
     String toString();
  }

• @FunctionalInterface
  public interface FI{
     int m1();
     default int m2(){ return 10; }
     String toString();
  }

• @FunctionalInterface
  public interface FI{
     String toString = "VALUE";
     boolean equals(Object o);
  }

Please select 2 options.

• int a; String b;
  Doer d = (a,  b)->b.substring(0, a);

• int a = 0; String b = "";
  Doer d = (a,  b)->b.substring(0, a)

• Doer d = (a, b)->b.substring(0, a);

• Doer d = (int a, String b)->b.substring(0, a);

• Doer d = a, b->b.substring(0, a);