Interfaces and Polymorphism - Java Concepts - page 589

mouseEntered
mouseExited
mousePressed
mouseReleased
javax.swing.AbstractButton
addActionListener
javax.swing.JButton
javax.swing.JLabel
javax.swing.JPanel
javax.swing.Timer
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REVIEW EXERCISES

΢ Exercise R9.1. Suppose C is a class that implements the interfaces I and J .
Which of the following assignments require a cast?

C c = . . .;
I i = . . .;
J j = . . .;

a. c = i ;

b. j = c ;

c. i = j ;

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΢ Exercise R9.2. Suppose C is a class that implements the interfaces I and J ,
and suppose i is declared as

I i = new C();

Which of the following statements will throw an exception?

a. C c = (C) i ;

b. J j = (J) i ;

c. i = (I) null ;