CSE205- QUIZ #4 INTERFACE & ARRAY
In Java, polymorphic method binding occurs:
A. at run time
B. at compile time
C. never
D. when a programmer writes the code
E. during the testing phase of software development - Answer -A. at run time
In Java, a(n) ___________________ is a collection of constants and abstract methods
A. polymorphic reference
B. abstract class
C. implementation
D. interface - Answer -D. interface
In order to create a class that implements an interface, the __________________
keyword is used
A. extends
B. interfaces
C. implements
D. finalizes
E. abstracts - Answer -C. implements
Which of the following methods are included with any object that implements the
Iteratorinterface?
A. next
B. hasNext
C. toString
D. all of the above
E. a and b - Answer -D. all of the above
Explanation: The Iterator interface specifies that all objects that implement it must have
the hasNext and next methods. Since all objects in Java are a subclass of the
Objectclass, it will also include the toStringmethod
Let Animal be an interface. Then it is possible to create an object by instantiating the
Animal interface:
true
false - Answer -false
Which of the following array declarations are invalid?
A. int [] grades = new int[5];
B. int grades [] = new int[5];
C. int [] grades = {91,83,42,100,77};
