collection class

1.== and equals1) a==b is an address comparison, and a.equals (b) is a comparison of values.2) The String class is the final immutable class, and a change to string will cause a new string object to be generated.3) The "ABC" form is assigned to the

This section focuses on the differences between several implementation classes of the list interface:1. Thread Safetyvectors are thread-safe, while ArrayList and LinkedList are non-thread-safe. from the source code, we know that the methods in the

"List Interface": A mutable array that allows all types of elements to be saved, including NULL, elements can be duplicated, saved in order of addition"Common Implementation Class": Recommended with ArrayListArrayList: Faster index access (but

1). ArrayList? ArrayList maintains an array of objects. If new ArrayList () is called, it defaults to an array of size=10.? Each add operation checks the array capacity, if not enough, re-sets a new array with an initial capacity of 1.5 times times

I. Introduction of LinkedListSince LinkedList is a dual-ended queue that implements Deque, LinkedList can be used as a queue and as a stack, using pop (), push (), Peek () when LinkedList as a stack. The way to note is that the LinkedList is the

Afrosiab BrotherOriginally from: https://bbs.ichunqiu.com/article-1618-1.htmlSeries Article albums:Python Dafa's Farewell Script Kid seriesDirectory: 0x05 High-Precision dictionary generation script writing Explanation of the 0x06 queue

Collection is a collection of objects, the Collection has two sub-interfaces List and set,list can be obtained by subscript (".)" To get the value, the value can be repeated , and the Set can only be used by the cursor to take the value, and the

The following code mainly calls 2 common functions of the tool class, Singletonlist and EmptylistString[] init = {"One", "one", "three", "one", "one", "three"}; List List = new arraylist (arrays.aslist (init)); SYSTEM.OUT.PRINTLN (list); List.add

Do not say the pattern of the problem, look at a > inside examples.The boss wants to see the company's various projects. (I know I have a big head look at this overview, see the code.)Sample Program V1Package iterator;/** * @author cbf4life

I. Generics (GENERIC)Because the elements put into the collection by default are object types, it is not possible to see their own types, when the operation of these elements need to be transformed to be available, so inefficient and error-prone,

Dictionary1. Fast enumeration Forin runtime cannot change internal dataFor ( Inch) {} //object//ArrayFor (contact *contact in friends) { [contact show]; }Determine if empty nsstring *ns ==nil Nsinteger inte==0A. DictionaryA dictionary? is used to

1 /**2 * Created by Administrator on 2015/4/14.3 */4 functionSet () {5 This. Values = {};6 This. N = 0;7 This. add.apply ( This, arguments);8 }9Set.prototype = {TenAddfunction () { One for(vari = 0; i ) { A

In this project development encountered the dynamic deletion of some elements in ArrayList.The correct approach is to:1 for (int i = 0, Len = list.size (), i ) { 2 if(List.get (i) = = 1) { 3 list.remove (i); 4 len--; 5

When the underlying implementation involves scaling up, the container or reassigning a larger contiguous memory (if the discrete allocation does not need to be redistributed, the discrete allocation is the dynamic allocation of memory when inserting

Attributes marked as transient are not saved when the object is serializedInt[] arr1 = {1, 2, 3, 4, 5};int[] arr2 = arrays.copyof (arr1, new_length);//arrays is an array of tool classesArrayList's ToArray method of converting to a static array is

The relationship between Map and setMap and set are really good friends, there are countless links.Map can be seen as an extension of set, because when the contents of a set are stored in the form of a key-value value pair, the set can actually be

Structure diagram: Collection ├list │├linkedlist │├arraylist │└vector │└stack └set map ├hashtable ├hashmap ----------------------------------------------------------------------The Collection interface collection is the most basic

  This is its own previous written a PHP collection class, has been used, I feel very simple and powerful, as long as the knowledge of a little selector can be collected any page, but also support HTTPS page, do a simple collection enough to use the

1. Common methods of the list interfaceThe list interface inherits the collection interface, so it contains all the methods in the collection. The list interface also provides a number of common methods that are appropriate for you, because lists

Snoopy is a PHP class, used to simulate the browser's function, you can get Web content, send forms, can be used to develop a number of acquisition procedures and thief programs, this article details the use of Snoopy tutorial. Some features of