Answer: enum and subclassing : Questions « Object Oriented « SCJP

B


Enums may not extend or be extended.

6.13.Questions
	6.13.1.	Is it legal enums: enum Animals {int age;LION, TIGER, DOG;}
	6.13.2.	Answer: enum and underline value
	6.13.3.	Is it legal enums:enum Animals {LION, TIGER, DOG;int weight;}
	6.13.4.	Answer: enum definition in a class
	6.13.5.	Is it legal enums?
	6.13.6.	Answer: enum, underline value and constructor
	6.13.7.	Is it legal enums(enum and constructor)?
	6.13.8.	Answer: enum and constructor
	6.13.9.	Which of the following may override a method whose signature is void a(float f)?
	6.13.10.	Answer: method signature and override
	6.13.11.	An enum definition should declare that it extends java.lang.Enum(True/False).
	6.13.12.	Answer: enum definition and java.lang.Enum
	6.13.13.	An enum may be subclassed(True/False).
	6.13.14.	Answer: enum and subclassing
	6.13.15.	An enum may contain public method definitions(True/False).
	6.13.16.	Answer: enum and methods
	6.13.17.	An enum may contain private data.
	6.13.18.	Answer: enum and data
	6.13.19.	An enum definition may contain the main() method of an application(True/False).
	6.13.20.	Answer: enum and main method
	6.13.21.	You can call an enum's toString() method(True/False).
	6.13.22.	Answer: enum and toString() method
	6.13.23.	You can call an enum's wait() method(True/False).
	6.13.24.	Answer: enum and wait method
	6.13.25.	You can call an enum's notify() method(True/False).
	6.13.26.	Answer: enum and notify method
	6.13.27.	Which are incorrect class declarations?
	6.13.28.	Answer: class declaration
	6.13.29.	What is the output from the following code
	6.13.30.	Answer: final variable
	6.13.31.	What is wrong with the following code?
	6.13.32.	Answer: local variable
	6.13.33.	Which of the following constructor signatures must exist in the Demo class for DerivedDemo to compile correctly?
	6.13.34.	Answer: constructor and class hierarchy
	6.13.35.	Which is a correct class based on the following interface?
	6.13.36.	Answer: class and interface implementation
	6.13.37.	What is the result when trying to compile and run the following code(class definition hierarchy)?
	6.13.38.	Answer: class definition hierarchy
	6.13.39.	What is the result when trying to compile and run the following code(final and class hierarchy)?
	6.13.40.	Answer: final and class hierarchy
	6.13.41.	Cohesion is to hide implementation details(True/False)
	6.13.42.	Answer: cohesion
	6.13.43.	Cohesion is to make sure that classes know about other classes only through their APIs(True/False)
	6.13.44.	Answer: cohesion(2)
	6.13.45.	Cohesion is to make sure that a class is designed with a single, well-focused purpose(True/False)
	6.13.46.	Answer: cohesion(3)
	6.13.47.	Cohesion is to allow a single object to be seen as having many types(True/False)
	6.13.48.	Answer: cohesion(4)
	6.13.49.	Will the following code compile(class hierarchy)?
	6.13.50.	Answer: class hierarchy
	6.13.51.	What is the result when trying to compile and run the following code(class hierarchy and override)?
	6.13.52.	Answer: class hierarchy and override
	6.13.53.	What is the result(method overload)?
	6.13.54.	Answer: method overload
	6.13.55.	What is the result(polymorphism and static method)?
	6.13.56.	Answer: polymorphism and static method
	6.13.57.	What is the result(three level class hierarchy)?
	6.13.58.	Answer: three level class hierarchy
	6.13.59.	What is the result(constructors and superclass)?
	6.13.60.	Answer: constructors and superclass
	6.13.61.	What is the result(Polymorphism and instance methods)?
	6.13.62.	Answer: Polymorphism and instance methods
	6.13.63.	What is the result(overloaded and var-args methods)?
	6.13.64.	Answer: overloaded and var-args methods