EnumSet complementOf(EnumSet e): 创建一个其元素类型与指定EnumSet里元素类型相同的EnumSet集合,新EnumSet集合包含原EnumSet集合所不包含的、此类枚举类剩下的枚举值(即新EnumSet集合和原EnumSet集合的集合元素加起来是该枚举类的所有枚举值)。 EnumSet copyOf(Collection c): 使用一个普通集合来创建EnumSet集合。 EnumS...
packagecom.alpari;importjava.util.ArrayList;importjava.util.Collection;publicclassDemoCollection{publicstaticvoidmain(String[] args){// 创建集合Collectioncollection=newArrayList();// 添加元素collection.add("java"); collection.add("c++"); System.out.println("元素个数 "+collection.size());// 打印:...
*/publicstaticvoidmain(String[]args){TreeSettreeSet=newTreeSet();treeSet.add(123);treeSet.add(456);treeSet.add(-456);treeSet.add(46);treeSet.add(-1);treeSet.add(0);//treeSet.add("aa");Iteratoriterator=treeSet.iterator();while(iterator.hasNext()){//从小到大遍历输出(可以按照添加对...
在Java中,TreeSet和TreeMap的性能如何? 1.TreeSet:数据元素可以排序且不可重复。 对比: (1)Set接口:HashSet,元素必须重写hashcode和equals方法。 (2)TreeSet:只要可以排序即可。去重:比较等于0即重复。 TreeSet数据排序两种方式: 注意:TreeSet是在添加数据时进行排序,数据更改不会影响原来的顺序,因此不能修改类中...
Constructs a new tree set containing the elements in the specified collection, sorted according to the natural ordering of its elements. TreeSet(IComparator) Constructs a new, empty tree set, sorted according to the specified comparator. TreeSet(IntPtr, JniHandleOwnership) A constructor used wh...
Exception in thread "main" java.lang.ClassCastException: com.frank.chapter22.TreeSetTest$Goods cannot be cast to java.lang.Comparable [Goods{name='Iphone4S', price=500.0}, Goods{name='Iphone5', price=800.0}, Goods{name='Iphone6S', price=2500.0}, Goods{name='Iphone7S', price=4500.0}, ...
Exception in thread "main" java.lang.ClassCastException: Bird cannot be cast to java.lang.Comparable at java.util.TreeMap.compare(Unknown Source) at java.util.TreeMap.put(Unknown Source) at java.util.TreeSet.add(Unknown Source) at com.sedion.bysocket.collection.TreeSetTest.main(TreeSe...
Exception in thread "main" java.lang.ClassCastException: Bird cannot be cast to java.lang.Comparable at java.util.TreeMap.compare(Unknown Source) at java.util.TreeMap.put(Unknown Source) at java.util.TreeSet.add(Unknown Source) at com.sedion.bysocket.collection.TreeSetTest.main(TreeSe...
Java documentation for java.util.TreeSet.TreeSet(java.util.Collection<? extends E>). Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License. Applies to .NET...
public TreeSet(Collection<? extends E> c) { this(); addAll(c); } //构造一个与指定有序 set ...