Iterator 接口的使用 所有的Collection接口类都有一个iterator方法

/*

* Iterator 接口的使用 所有的Collection接口类都有一个iterator方法

*以返回一个实现了Iterator接口的对象

*/

import java.util.*;

class Name

{

private String firstname;

private String lastname;

Name(String firstname,String lastname)

{

this.firstname = firstname;

this.lastname = lastname;

}

public String getfirstname()

{

return firstname;

}

public String getlastname()

{

return lastname;

}

public String toString()

{

return firstname+"."+lastname;

}

}

public class TestIterator

{

public static void main(String[] args)

{

Collection c = new HashSet();

c.add(new Name("f1","l1"));

c.add(new Name("f2","l2"));

c.add(new Name("f3","l3"));

Iterator i = c.iterator();

while(i.hasNext())

{

Name n = (Name) i.next();//强制转换

System.out.println(n.getfirstname());

// System.out.println(i.next().getfirstname());//这样也能输出

}

}

}