comparable interface

I. Basic knowledgeJava Collection FrameworkWhat is a 1.Java set frame? What are some of the advantages of a collection framework?There are collections in each programming language, and the original Java version contains several collection classes:

In Java we often use the comparable interface to implement sorting, where CompareTo is implementing the interface method. We know that CompareTo returns 0 means that two objects are equal, a positive number represents greater than, and a negative

List: (ordered, can be repeated) by subscript index----ArrayList variable array, randomly finds----linkedlist linked list, no matter where the insertion is deleted fast----Vector efficiency is lower than ArrayList. But can be used for multi-threaded

I. array: An array is a set of variables of the same type and can be referenced by a common name. Arrays can be defined as any type, which can be one-dimensional or multi-dimensional. A special element in the array is to access it by subscript.

One, the collection:1, Features: storage objects, variable length, storage object types can be different;2. Set Frame:2 ) Collection(1) List: Ordered, elements repeatable, indexed(Add (index, Element), add (Index, Collection), remove (index), set

Collection: A collection container that stores object data.First, single-column collection----------| Collection the root interface of a singleton collection----------------| List if it is a collection class that implements the list interface, has

　　1, the classification of the collection (all located under the Java.util package)Set Frame system 1) collection is the parent class interface of the collection (except for the map collection), and the Set and list collections are inherited from

Map is a two-column set interface, if the map interface is implemented, the characteristic is that the data is in the form of key-value pairs, the keys cannot be duplicated, and the values can be duplicated. Java mainly has HashMap, TreeMap,

(i) List and array①list default Sort code:public static void Main (string[] args) { list List = new arraylist<> (); List.add ("A-li"); List.add ("No B Settling"); List.add ("Hee X Hee"); List.add ("One Y One"); List.add ("Pass C");

Personal blog Sync release: Effective java-Reading notes-Chapter III methods that are common to all objectsChapter III methods that are common to all objectsAll non-final methods (equals, Hashcode, toString, clone, Finalize) have explicit general

Let's start by talking about the meaning of the sorted return value. For the two object,o1 and O2 that participate in the comparison, if the return value of the function is positive, the O1 is ranked behind the O2, the return value is negative, and

In Java, it often involves the ordering of object arrays, which involves the comparison of objects.The usual comparisons between objects can be seen in two ways:The first aspect: whether the address of the object is the same, that is, whether to

Array??The array in Java is a class??The array in Java is a special class and a bit different from C + + , since the array in Java is a class, is the class name of the string array and the integer array the same? The answer is no, the class name of

Shows a complete diagram of the Java Container Class library, including abstract classes and legacy artifacts (excluding queue implementations).The commonly used container is represented by a thick black wireframe, a dotted box represents an

Implement custom sorting of objects with two examples1, realize comparator interface.1 Importjava.util.ArrayList;2 Importjava.util.Collections;3 ImportJava.util.Comparator;4 Importjava.util.List;5 6 Public classStudentcomparatorimplements

"Concept of containers"Container: A series of instances provided by the Java API for storing objects in a program."Container API"The container API provided by J2SDK is located in the Java.util package.{Collection[set (hashset,linkedlist), Srraylist]}

1: Set Collection (Single column collection) List (ordered, repeatable) ArrayList The underlying data structure is an array, query fast, delete slow thread unsafe, efficiency High Vector underlying data structures are arrays, fast queries, additions

Interface--------------------------------------------------------------------------------One, interface (is a specification)1. Interface name/interface files are similar to classes and are also written in. java files2. Keyword Interface Interface

A first exampleJava code /* To compare, let your class implement the comparable interface and rewrite it in the sort order you want CompareTo *map just provides a sort of key, but when we need to sort the values, we provide our own comparators.

Java provides a lot of useful tool classes for development, which can help us to write concurrent programs more efficiently, and we'll cover the use of these utilities in this article.ThreadLocalThe Threadlocal class is used to solve the problem of