First step
The operation is very simple, we just open "mobile phone Taobao" on the phone and then we find the baby we want to buy the following figure shows
Second Step
And then in the open interface, we click on the "Baby page" and go down to slide
Third Step
In the Open interface we click "Go into the shop" to open the entry, details as follows
Fourth Step
Then you'll see a "collection", as shown in the following figu
It was originally thought to be solved with a simple for loop, but ignoring the removal would change the size of the collection and some errors or incorrect data;
The correct way: iterator iterator; Below is a small example of the Web, and finally posted their own wrong code to help memory.
Import java.util.ArrayList;
Import Java.util.Iterator;
public class Testlist {public static void main (string[] args) {test1 ();
Test2 ();
Test3 ();
publi
Collection interface:1. The collection can be understood as a dynamic array of objects, but the contents of the objects in the collection can be arbitrarily expanded.This means that the operation in the collection is more convenient, easy to add or delete2. Features of the collection:High performanceEasy to expand and
ArticleDirectory
Differences between parallelism and concurrency
Now I think that you should review or learn the knowledge from the global perspective, and then sort out the outline, so that you can have a comprehensive and consistent understanding of this knowledge, it is also conducive to future review, which of the following statements are not clear and targeted?
Speaking of garbage collection, before garbage
The collection interface is the basis of the set-up framework. It declares the core method of all collections. These methods are summarized in the following table.Because all collections are implemented collection, it is necessary to be familiar with it by having a clear understanding of the framework. There are several ways to throw a unsupportedoperationexception.
SN
Method and Descript
Java Tour (18)--Basic data type Object wrapper class, collection frame, data structure, collection,arraylist, iterator iterator,list use
Java defines all things as objects, and we want to use data types that can be referenced.
I. Object wrapper classes for basic data types
The left is the base data type, and the reference data type
BYTE byte
int Integer
Long Lon
Understand Python garbage collection mechanism and python garbage collection mechanism
I. Garbage Collection MechanismIn Python, garbage collection is based on reference count, supplemented by generational collection. The defect of reference count is the issue of circular re
Collection
For the understanding of collections, a collection is a container for storing and managing objects of other objects
Collection, first understand the parent interface of all collections----collection
Feature: Store any object element
Method
Boolean Add (Objec
------Java Training, Android training, iOS training,. NET training, look forward to communicating with you! -------First, List collectionThe list collection represents an ordered, guest-repeating collection of elements in which each element has its corresponding sequential index. ListCollections allow you to use duplicate elements, which can be indexed to access the col
Java Collection framework (I) and java Collection frameworkJava Collection framework (I)
Because the collection framework in Java has a lot of content, it is divided into three parts to introduce the Java Collection framework, the content is from the shortest to the deep, if
. Net garbage collection-Principle Analysis and. net garbage collection
This article cited from: http://www.cnblogs.com/wilber2013/p/4357910.html
During the development of. NET programs, since the garbage collection mechanism in CLR manages allocated objects, programmers can ignore the time when objects are released. However, it is necessary to understand the ga
The 1:set collection consists of the implementation classes of the set interface and the set interface, and the set interface inherits the collection interface because it contains all the methods of the collection interface.2: Because duplicate values are not allowed in the set interface, you can use the AddAll () method in the Set
Garbage collection in Jvm and Jvm garbage collection
I. Concept of garbage collection
Memory collection in Java is the memory collection during Jvm runtime. The areas to be recycled include the method area and Java heap. Because of program counters, Java Virtual Machine stac
Java garbage collection mechanism and java garbage collection
When it comes to Garbage Collection (GC), many people naturally associate it with Java. In Java, programmers do not need to worry about the problem of dynamic memory allocation and garbage collection. All this is handled by JVM.
As the name implies, garbage
The following content is based on jdk1.7.0_79 source code;What is a set iterator fast failure behaviorTake ArrayList as an example, in the case of multithreaded concurrency, if there is a thread modifying the structure of the ArrayList collection (insert, remove ...). , while another thread is iterating through the elements in the collection with an iterator, throwing an concurrentmodificationexception exce
Collection1. Overview of the collection(1). The reason for the collectionWe are learning object-oriented language, and object-oriented language is the description of things through objects, in order to facilitate the operation of multiple objects, we must make this objectStorage, and to store multiple objects, it cannot be a basic variable, but rather a variable of a container type, what we have learned at the moment is only inside, what are the conta
We all know the Java garbage collection mechanism, Java has its own garbage collector to automatically recycle garbage. I have been aware of the garbage collection mechanism before the Java garbage collector is automatically recycled garbage, there are two ways to know about finalize and system, and people tell me that you know that Java virtual machines have garbage co
Map InterfaceThe Map collection stores data in a key-value pair (Key-value) where the key cannot be duplicated and the value can be duplicated.Common classes are HashMap, TreeMap and propertiesHashMap classIf, now I have a collection that stores a batch of WiFi names and passwords, now requires a quick name to find the password. Such a requirement is very difficult to implement with the list
1. The collection framework acts as a container for processing objects. The basic interface is collection. Compared with arrays, the collection framework can only store objects, but its length is variable. The relationship diagram of the Collection framework is as follows:
The main content is list, set, map,
The eleme
When it comes to the collection collection, we have to mention arrays, and the arrays in Java provide great convenience for us to store large amounts of data, butis an array also has many shortcomings, not flexible enough 1. The length of the array defined is fixed, but the length of the data in the actual development is often not fixed. 2. Only data of the same type can be stored in an array, but i
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