Java的Comparable接口就类似C++中的重载<=,而Java的Comparator接口就类似C++中为sort而定义的comp函数。 一、Comparable 接口 Comparable接口又称为内部比较器 接口定义 Interface Comparable<T>// 'T' - the type of objects that this object may be compared to 接口抽象方法: intcompareTo(T o);// Parameters...
A comparison function, which imposes a total ordering on some collection of objects. Comparators can be passed to a sort method (such as Collections.sort or Arrays.sort) to allow precise control over the sort order. Comparators can also be used to control the order of certain data structures ...
Use the DepartmentComparator to Sort Elements in Java Modify the Program Above Using the lambda Function in Java 8 This article defines what a sort comparator in Java is and demonstrates how you can use it in processes. We’ve included programs you can follow to help you understand this ...
优点是可以按照多种方式排序,你要按照什么方式排序,就创建一个实现Comparator接口的排序方式类,然后将该排序类的对象传入到Arrays.sort(待排序对象,该排序方式类的对象) 1.Compable接口代码 import java.util.Arrays; /** * 使用Comparable接口:让待排序对象所在的类实现Comparable接口,并重写Comparable接口中的compare...
Collections.sort(List<T> list,Comparator<? super T> c); 1. 2. 3.使用场景 什么场景需要做比较,那么什么场景就是Comparator接口的用武之地,我总结的两个场景: 1. 排序,需要比较两个对象谁排在前谁排在后(排序也可以让类实现Comparable接口,实现后该类的实例也具有排序能力)。
Comparator is also used for sorting. We can sort list, arrays, Collections using comparator in java. Comparator interface is used to order the objects of user-defined class. The compare Method: int compare(Object obj1, Object obj2)
We introduced the notion of a Comparator in Java, which is used to specify the sort order of a particular class. Let's start with an example to sort Strings by their length. We thus want to write a Comparator that compares Strings. So the general format of our Comparator will be as ...
Learn to sort aListof objects by a field value in Java using theComparableinterface (default sort order) andComparatorinterface (additional custom sort orders). Quick Reference Listlist=...;Comparatorcomparator=Comparator.reverseOrder();//Create custom order as needed//1 - List.sort()list.sort(...
A comparison function, which imposes atotal orderingon some collection of objects. Comparators can be passed to a sort method (such asCollections.sortorArrays.sort) to allow precise control over the sort order. Comparators can also be used to control the order of certain data structures (such ...
有点像这样: Collections.sort(list, X.attr); 请您参考如下方法: 假设您实际上有一个List<AnObject>,您所需要的只是 list.sort(Comparator.comparing(a -> a.attr)); 如果您不使用公共(public)字段而是使用访问器方法来使代码干净,那么它会变得更加干净: ...