知到答案面向对象程序设计（山东联盟）智慧树答案_2022年

第八章

A(n) _____ class cannot be instantiated. ( )
答案:abstract.
Non-abstract classes are called ________. ( )If the superclass contains only abstract method declarations, the superclass is used for ________. ( )Which of the following could be used to declare abstract method method1 in abstract class Class1 (method1 returns an int and takes no arguments)? ( )Which of the following statements about abstract superclasses is true? ( )Consider classes A, B and C, where A is an abstract superclass, B is a concrete class that inherits from A and C is a concrete class that inherits from B. Class A declares abstract method originalMethod, implemented in class B. Which of the following statements is true of class C? ( )When a superclass variable refers to a subclass object and a method is called on that object, the proper implementation is determined at execution time. What is the process of determining the correct method to call? ( )Every object in Java knows its own class and can access this information through method . ( )Assigning a subclass reference to a superclass variable is safe ________. ( )Classes and methods are declared final for all but the following reasons: ( )