相关疑难解决方法(0)

什么是迭代器和集合？这两个有关系吗？

// the interface definition
Interface Iterator {
    boolean hasNext();
    Object next(); // note "one-way" traffic
    void remove();
}

// an example
public static void main (String[] args){
    ArrayList cars = new ArrayList();

    for (int i = 0; i < 12; i++)
        cars.add (new Car());

    Iterator it = cats.iterator();

    while (it.hasNext())
        System.out.println ((Car)it.next());
}

Interface Iterator是否单独预定义了这些方法名称或用户定义了哪些方法名称？下面这四行实际上讲的是什么？

cars.add (new Car());
Iterator it = cats.iterator();
while (it.hasNext())
    System.out.println ((Car)it.next());

谢谢.我正在阅读一本收藏的书.