[单项选择题] 阅读下面代码 class InterestTest ______ ActionListener { … public void actionPerformed(ActionEvent event) { double interest=balance * rate/100: balance+=interest: NumberFormat format=NumberFormat.getCurrencyInstance(); System.out.printlb("balance="+Formatter.format(balance)); } Private double rate; } 在下画线处,应填入的正确选项是
A.implementation
B.inheritance
C.implements
D.extends
正确答案:C
参考解析:关键字extends指明该类是子类,它的父类名紧跟在后,子类与父类之间有继承关系。关键字implements指明该类实现的接口,后跟接口名列表。因为ActionListener是时间监听器,是接口,所以这里要填入implements,故答案为C。


![[单项选择题] 阅读下面代码 class InterestTest [单项选择题] 阅读下面代码 class InterestTest](http://www.mshxw.com/aiimages/31/481271.png)
