list.add("world");list.add("world");list.add("world");list.add("world"); list.add("java");list.add("hello");list.add("world");list.add("java");list.add("world"); for (int x = 0; x < list.size() - 1; x++) { for (
ArrayList list =newArrayList(); list.add("a"); list.add("b"); list.add("c"); Iterator it = list.iterator(); while(it.hasNext()){ String str = (String) it.next(); System.out.println(str); } } } 运行结果: a b c 可以看到,Iterator可以不用管底层数据具体是怎样存储的,都能够通过...
*/for(int i=list.size()-1;i>=0;i--){System.out.println(list.get(i));}/** 方法五:Iterator遍历 优点:简洁 缺点: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 */for(Iterator it=list.iterator();it.hasNext();){System.out.println(it.next());}/** 优点:简洁结合泛型使用更简洁 ...
Iterator it = col.iterator(); while(it.hasNext()) { Object obj = it.next();///当需要使用子类对象特有方法时,需要向下转型, 否则报错 if(it.next()instanceofString) {//“111” String s = (String)it.next();//是23456 System.out.println(s.length()); } } }...
Unlike the other abstract collection implementations, the programmer does not have to provide an iterator implementation; the iterator and list iterator are implemented by this class, on top of the “random access” methods: get(int), set(int, E), add(int, E) and remove(int). The documen...
(nonstatic) inner class. Note well that each instance contains an implicit* reference to the containing list, allowing it to access the list's members.*/privateclassArrayIteratorimplementsIterator<E>{/** Index of the next element to report. */privateintj=0;// index of the next element to...
1 for (String s : list) { 2 System.out.println(s); 3 } 1. 2. 3. 迭代器接口定义 首先来看下迭代器的接口定义如下: 1 public interface Iterator<E> { 2 3 boolean hasNext(); 4 5 E next(); 6 7 default void remove() { 8 throw new UnsupportedOperationException("remove"); ...
iterator(); // 获取列表的迭代器 while (iterator.hasNext()) { String element = iterator.next(); System.out.println(element); // 输出:apple, banana, orange } Object[] array = list.toArray(); // 将列表转换为数组 System.out.println(Arrays.toString(array)); // 输出:[apple, banana, ...
Returns true if this list iterator has more elements when traversing the list in the reverse direction. Enext() Returns the next element in the list and advances the cursor position. intnextIndex() Returns the index of the element that would be returned by a subsequent call to next(). Epr...
A ListIterator has no current element; its cursor position always lies between the element that would be returned by a call to previous() and the element that would be returned by a call to next(). An iterator for a list of length n has n+1 possible cursor positions, as ill...