注意:在上面的代码中,虽然 sortedLinkedHashSet 作为一个 LinkedHashSet 并不保证迭代顺序与排序顺序完全一致(因为它仍然遵循插入顺序的保证),但我们可以通过遍历这个集合并将其元素添加到一个新的 ArrayList 中来验证排序结果。这个新列表将显示排序后的顺序。
迭代顺序取决于Collection的迭代器的实现,在LinkedHashSet的情况下,迭代顺序是插入的顺序。因此,您的List将保留插入顺序。 您可以在 Javadoc 中看到这一点: java.util.ArrayList.ArrayList(Collection c) Constructs a list containing the elements of the specified collection,in the order they are returned by the ...
LinkedHashSet is very much likeArrayList(ordered) and HashSet (unique elements). It additionally guarantees the iteration order of elements (in order elements were inserted). A real life usecase for LinkedHashSet can be storing data from stream where stream may contain duplicate records in the ...
List<String> stringList =arrayList.stream().map(Animal::getName).collect(Collectors.toList()); System.out.println("检验是否倒序排序:"+stringList); List<String> strings =arrayList.stream().sorted(Comparator.comparing((Animal::getAge),Comparator.reverseOrder()) ) .map(Animal::getName).collect(...
值得注意的是,使用HashSet删除元素也只有1个方法,并不像使用ArrayList删除元素有2个重载: publicbooleanremove(Object o){returnmap.remove(o)==PRESENT; } 使用方法如下所示: // 删除不存在的元素"个人博客",返回falseSystem.out.println(platformSet.remove("个人博客"));// 删除存在的元素 "微信公众号",返回...
值得注意的是,使用HashSet删除元素也只有1个方法,并不像使用ArrayList删除元素有2个重载: public boolean remove(Object o) {return map.remove(o)==PRESENT;} 使用方法如下所示: // 删除不存在的元素"个人博客",返回falseSystem.out.println(platformSet.remove("个人博客"));// 删除存在的元素 "微信公众号"...
LinkedHashSet does maintain insertion order ---element 2 LinkedHashSet does maintain insertion order ---element 3 LinkedHashSet does maintain insertion order ---element 4 4. LinkedHashSet删除API的例子 remove(Object o) 从LinkedHashSet中删除一个元素(如果该元素不存在于LinkedHashSet 中,remove()方法...
LinkedHashSet implements Set interface and extends HashSet class. LinkedHashSet maintains insertion order, so when you will be able to access elements in the order they were inserted like ArrayList. Example: LinkedHashSetMain.java 1 2 3
LinkedHashSetdoes maintain insertion order---element2 LinkedHashSetdoes maintain insertion order---element3 LinkedHashSetdoes maintain insertion order---element4 4. LinkedHashSet删除API的例子 remove(Object o) 从LinkedHashSet中删除一个元素(如果该元素不存在于LinkedHashSet中,remove()方法返回false) ...
Values() // []int{5,1} (random order) set.Clear() // empty set.Empty() // true set.Size() // 0 } TreeSet A set backed by a red-black tree to keep the elements ordered with respect to the comparator. Implements Set, IteratorWithIndex, EnumerableWithIndex, JSONSerializer and ...