它使用 ArrayList 对象,但一般原则适用于任何类型的集合。 当然,ListIterator 只对那些实现了 List 接口的集合可用。 importjava.util.*;publicclassIteratorDemo{publicstaticvoidmain(String args[]){// 创建数组列表ArrayList al =newArrayList();// 将元素添加到数组列表al.add("C"); al.add("A"); al.add...
原文:https://www.geeksforgeeks.org/how-to-use-iterator-in-java/ “迭代器”是一个属于集合框架的接口。它允许我们遍历集合,访问数据元素并移除集合中的数据元素。 java.util 包有公共接口迭代器,包含三种方法:布尔hasNext() :如果 Iterator 有更多元素要迭代,则返回 true。 Object next() :它返回集合中的...
you cannot use the iterator in a “for” loop. You can use the iterator in an “if” block in cases when the corresponding collection is expected to have only one element or you are interested in only the first element of the collection: ...
Every collection class has aniterator() methodwhich returns an iterator object to the beginning of the collection elements. By using this object, we can access each element in the collection and each element at a time. To use an Iterator to traverse the collection follow these steps: 1. Obta...
Java Iterable、Iterator Iterable publicinterfaceIterable<T>{Iterator<T>iterator();...} Iterable是可以迭代的一系列元素的表示。它没有任何迭代状态,例如“当前元素”。相反,它有一个生成迭代器的方法。 Iterator publicinterfaceIterator<E>{booleanhasNext();Enext();voidremove();...}...
Close the iterator. Use theNamedIterator.closemethod to do this. Example The following code demonstrates how to declare and use a named iterator. The numbers to the right of selected statements correspond to the previously-described steps.
http://stackoverflow.com/questions/6863182/what-is-the-difference-between-iterator-and-iterable-and-how-to-use-them Iterator is an interface, which has implementation for iterate over elements. Iterable is an interface which provides Iterator. ...
第三种遍历方法:使用Iterator迭代器接口进行相关遍历 import java.util.*; public class demo { public static void main(String[] args) { //创建了一个ArrayList对象:list List<String> list = new ArrayList<>(); //向list中添加元素 list.add("Hello"); ...
The following method shows you how to use anIteratorto filter an arbitraryCollection— that is, traverse the collection removing specific elements. static void filter(Collection<?> c) { for (Iterator<?> it = c.iterator(); it.hasNext(); ) ...
Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's iterator (optional operation). AddAll(Int32, ICollection) Inserts all of the elements in the specified collection into this list at the specifie...