design patterns explained simply

access a public variable, the name of the main object must be repeated. He doesn't like it either. When using module mode, you must switch to object literal notation to make a method public.He creates a new pattern that simply defines all of the functions and variables within the private scope and returns an anonymous object that has a pointer to a private function that he wants to show as public.Example:var revealingmodule= (function () { var pri

Principles of design patterns single responsibility principles For a single responsibility, each class is only responsible for one function, or each class is only responsible for one responsibility. This will not affect too many contacts when you need to modify it,Rys replacement principle Definition 1:If there is an object O2 of Type T2 for every object O1 of Type T1, so that all program P defined by T1 ca

defines the skeleton of the algorithm. (2) concrete templates (concrete template): The concrete template is the subclass of the abstract template, which implements the primitive operation in the abstract template. The class diagram for the template method pattern structure is shown in two:Figure two: Class diagram of template method pattern1.3Template Methodadvantages of the model(1) The detailed template implementation details do not alter the framework of the entire algorithm by giving the ma

One of the several javaScript design patterns-the Single Mode JavaScript is a weak type, dynamic, prototype-based language. This language feature makes it very easy, It is even common to implement some of these modes. The idea of the standalone mode is to ensure that a specific class has only one instance. This means that when you use the same Class to create a new object. In javaScript, there are no classe

somewhat interesting topic. We have summed up the market on the common five kinds of design patterns, for everyone according to the actual situation of their products for reference. 　　1. Ask directly, then pray Many apps will be able to ask for permission in the process of first use. It is the simplest implementation, but the most likely to be rejected (except for products that are big enough to be trus

When instantiating a class using new, the implementation is used instead of the interface, and the code is bundled with a specific class that causes the code to become more brittle and inflexible, and the loosely coupled oo pattern can be used to relieve it.Factory: Encapsulates the creation of objects, handling the details of creating objectsStatic Factory: Define a simple factory with a static method. Pros: You do not need to create an instantiation of a factory class. Disadvantage: You cannot

objects.Advantages:1. Subject when sending the broadcast notice, do not need to specify the specific observer,observer can decide whether to subscribe subject notice;2. High cohesion, low coupling, can be independently changed.defects:1. Loose coupling causes the code relation to be not obvious, sometimes may be difficult to understand;2. If a subject is subscribed by a large number of observer, there may be an efficiency issue when broadcasting a notification. Copyright NOTICE: This article fo

and the proxy object, so that the proxy object can be used wherever the target object can be used.target Object role: defines the target object that the proxy object represents.proxy Object role: the proxy object contains a reference to the target object, so that the target object can be manipulated at any time, and the proxy object provides the same interface as the target object so that the target object can be substituted at any time. Proxy objects typically perform an operation before or af

Command mode : Sometimes you need to send a request to some object, but do not know who the recipient of the request is, and do not know what the requested operation is, at this time want to use a loosely coupled way to design the software, so that the request sender and the request receiver can eliminate the coupling relationship between each other.The argument is very complex, simply to want to really do

system (scalability - increase, flexibility / modifiable - repair, pluggable - testability) and reusability. The Richter substitution principle (LSP)From the "open-closed" principle, it can be seen that the key to object-oriented design is abstraction, which requires the use of inheritance, from abstraction to materialization, and whether the inheritance relationship needs to be validated by using the Richter substitution principle (Liskov sub

, generally long-term, and the relationship between the two is generally equal.(2) In the dependency relationship, it is simple to understand that a class A uses another Class B, which is contingent, temporary, and very weak, but changes in class B affect a.4. Comprehensive comparisonThese relationships are semantically level, so it is not possible to completely differentiate the relationships from the code level, but in general, the latter relationships are shown in the following ways:Combinati

is stored so that the waiter does not need to know, decouple with the waiterIterator interface:1 Public Interface Iterator { 2 boolean hasnext (); 3 Object Next (); 4 } Dinner Menu iterator implementation, for its underlying array storage method:1 Public classDinermenuiteratorImplementsIterator {2 menuitem[] items; 3 intPosition = 0; 4 5 Publicdinermenuiterator (menuitem[] items) {6 This. Items =items; 7 } 8 9 PublicObject Next () {TenMenuItem

In the object-oriented design model, there are six main relationships between classes: dependency, association, aggregation, combination, inheritance, and implementation. Their Coupling Degree increases sequentially. 1. Dependency) Description: It can be simply understood that a class A uses another class B, and this relationship is contingent, temporary, and very weak, but changes in Class B will affect. I

Reprinted please indicate the source: http://blog.csdn.net/guolin_blog/article/details/8986299 This is a copy version of Java Design Pattern dialysis, which is specially provided for Ruby lovers. If you are not familiar with Ruby syntax, please refer: Analysis of Java design patterns -- Strategy) Today, your leader is eager to find you. I hope you can help him.

Analysis of Android source code design patterns and practices (23rd)Chapter 2 appearance Mode The appearance mode is one of the structural design modes. It is frequently used in development and is a common method for encapsulating APIs. Third-party sdks we often use are basically used in the appearance mode, which can shield users from many implementation detai

Combinatorial mode is a common design pattern for maintainability-oriented programming. Simply put, a class contains a set of collection of the current class as attributes of the class. This is a certain similarity to recursion. His goal is to establish a tree hierarchy between objects of the same type, and an upper object can contain multiple downlevel objects. For example, a menu can have many options, an

Single Duty principle (Responsibility Principle) Definition: A class should have only one cause of change. In layman's terms, a class is responsible for only one responsibility. The origin of the problem: class T is responsible for two different duties: responsibility P1, Responsibility P2. When a class T needs to be modified due to a change in the duty P1 requirements, it is possible to cause a normal function to malfunction P2 functionality. Solution: Follow a single responsibility principle.

implementation, easy to expand), and the Idao object usesAbstract Factory modeCreate.4.ConcreteDao implementation of Idao interface, focus on adding and deleting the logical implementation of the search, the implementation of the concrete implemented by DBHelper. Advantages: 1.Action can represent a lot of action, scalability is strong; 2. Use abstract Factory mode to easily convert database operations; 3.Control classes can implement redo and undo operations, and support transactions (a set of

) 2015 Han Xuepeng. All rights reserved.//#import @protocolwbteacherdelegate@required- (void) SendMessage;- (void) collectsomething;@end@interfaceWbteacher:nsobject@property (nonatomic, weak)ID Delegate;- (void) DoSomething: (int) tag;@end////WBTEACHER.M//Designpatternsdemo////Created by Han Xuepeng on 15/6/22.//Copyright (c) 2015 Han Xuepeng. All rights reserved.//#import "WBTeacher.h"@implementationWbteacher- (void) DoSomething: (int) Tag {if(!_delegate) { return; } Switch(tag) { Cas

instance. It returns //a singleton instance of a singleton objectGetInstance:function(options) {if(Instance = = =undefined) {Instance=NewSingleton (options); } returninstance; } }; return_static;}) (); varSingletontest =singletontester.getinstance ({pointx:5}); //Log the output of pointx just to verify it is correct//Outputs:5Console.log (SINGLETONTEST.POINTX);Whilst the Singleton have valid uses, often when we find ourselves needing it in JavaScript it's a sign that we could need t