就要考了,但是147中还有两题完全不明白,请高手解答。
74
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1. public class Mycircle {
2. public double radius;
3. public double diameter;
4.
5. public void setRadius(double radius) {
6. this.radius = radius;
7. this.diameter = radius * 2;
8. }
9.
10. public double getRadius() {
11. return radius;
12. }
13. }
Which statement is true?
A. The Mycircle class is fully encapsulated.
B. The diameter of a given MyCircle is guaranteed to be twice its radius.
C. Lines 6 and 7 should be in a synchronized block to ensure
encapsulation.
D. The radius of a MyCircle object can be set without affecting its
diameter.
答案是D。
问D是怎么得来的?
还有Mycircle class怎样写才是fully encapsulated?
Which two statements are true? (Choose Two)
A. An anonymous inner class can be declared inside of a method.
B. An anonymous inner class constructor can take arguments in some
situation.
C. An anonymous inner class that is a direct subclass that is a direct
subclass of Object can implement multiple interfaces .
D. Even if a class Super does not implement any interfaces, it is still
possible to define an anonymous inner class that is an immediate
subclass of Super that implements a single interface.
E. Even if a class Super does not implement any interfaces, it is still
possible to definean anonymous inner class that is an immediate
subclass of Super that implements multiple interfaces.
答案是AB。
B、C、D、E 都麻烦帮忙详细解释解释。
谢了。