哪位有天津高自考软件工程专业Java程序设计上机考试题

Java2程序员考试SCJP 试题解析2
例题5：

Which two demonstrate a "has a" relationship? (Choose two)

A. public interface Person { }

public class Employee extends Person{ }

B. public interface Shape { }

public interface Rectandle extends Shape { }

C. public interface Colorable { }

public class Shape implements Colorable

{ }

D. public class Species{ }

public class Animal{private Species species;}

E. interface Component{ }

class Container implements Component{

private Component[] children;

}

解答：D, E

点评： 在Java中代码重用有两种可能的方式，即组合（“has a”关系）和继承（“is a”关系）。“has a”关系是通过定义类的属性的方式实现的；而“is a”关系是通过类继承实现的。本例中选项A、B、C体现了“is a”关系；选项D、E体现了“has a”关系。

例题6：

Which two statements are true for the class java.util.TreeSet? (Choose two)

A. The elemen