importjava.util.HashSet;importjava.util.Set;publicclassSetExample{publicstaticvoidmain(String[]args){Set<String>set=newHashSet<>();set.add("Apple");set.add("Apple");set.add("Banana");set.add("Cherry");System.out.println(set);// prints [Apple, Banana, Cherry] (order may vary)}} 运...
如果hasNext()返回true之后还继续用Next函数的话,那么会怕抛出NoSuchElementException异常 为了更好的利用和实现多态,理解好基本collection接口才能更好的利用Collections Framework
其他部分可以从左向右看,比如Collection的Subinterfaces有List,Set以及Queue等。 packagejava.util;/*** An iterator over a collection. Iterator takes the place of Enumeration in * the Java collections framework. Iterators differ from enumerations in two * ways: * Iterators allow the caller toremove ...
java.util.Iterator 在Java中Iterator为一个接口,它只提供了迭代了基本规则,在JDK中他是这样定义的:对 collection 进行迭代的迭代器。迭代器取代了 Java Collections Framework 中的 Enumeration。迭代器与枚举有两点不同: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 1、迭代器允许调用者利用定义良好的语义在...
迭代:即Collection集合元素的通用获取方式。在取元素之前先要判断集合中有没有元素,如果有,就把这个元素取出来,继续在判断,如果还有就再取出出来。一直把集合中的所有元素全部取出。这种取出方式专业术语称为迭代。 java.util.Iterator接口:迭代器(对集合进行遍历) ...
Java Iterator Interface TheIteratorinterface of theJava collections frameworkallows us to access elements of a collection. It has a subinterfaceListIterator. All the Java collections include aniterator()method. This method returns an instance of iterator used to iterate over elements of collections....
import java.util.*;public class CollectionTest {public static void main(String[] args){Collection c = new ArrayList();//可以放入不同类型的对象c.add("hello");c.add(new Name("f1","l1"));System.out.println(c.size());System.out.println();}}class Name {private String firstName,lastNam...
An iterator over a collection.Iteratortakes the place ofEnumerationin the Java Collections Framework. Iterators differ from enumerations in two ways: Iterators allow the caller to remove elements from the underlying collection during the iteration with well-defined semantics. ...
> Iterator对象称为迭代器(设计模式的一种),主要用于遍历 Collection 集合中的元素。 > GOF给迭代器模式的定义为:提供一种方法访问一个容器(container)对象中各个元素,而又不需暴露该对象的内部细节。迭代器模式,就是为容器而生。 > Collection接口继承了java.lang.Iterable接口,该接口有一个iterator()方法,那么所有...
Iterators differ from enumerations in two ways: Iterators allow the caller to remove elements from the underlying collection during the iteration with well-defined semantics. Method names have been improved. This interface is a member of the Java Collections Framework. API Note: An Enumeration ...