( { // here you can define setting values // a.k.a. configuration constants maxwidth : 600, maxheight : 400, // you can also define utility methods gimmeMax : function() { return this.maxwidth + "x" + this.maxheight; }, // initialize init : func…

Principle Make variables shouldn't be changed stand out using all caps. Add constants as static properties to the constructor function. // constructor var Widget = function () { // implementation... }; // constants Widget.MAX_HEIGHT = 320; Widget.MAX…

7.1 Singleton The idea of the singleton pattern is to have only one instance of a specific class. This means that the second time you use the same class to create a new object, you should get the same object that was created the first time. var obj =…

Scenario You want to use just the methods you like, without inheriting all the other methods that you’ll never need. This is possible with the borrowing methods pattern, which benefits from the function methods  call() and apply(). // call() example…

Loop through arguments and copy every property of every object passed to the function. And the result will be a new object that has the properties of all the source objects. function mix() { var arg, prop, child = {}; for (arg = 0; arg < arguments.le…

Shallow copy pattern function extend(parent, child) { var i; child = child || {}; for (i in parent) { if (parent.hasOwnProperty(i)) { child[i] = parent[i]; } } return child; } Deep copy pattern function extendDeep(parent, child) { var i, toStr = Obje…

No classes involved; Objects inherit from other objects. Use an empty temporary constructor function  F().  Set the prototype of  F() to be the parent object. Return a new instance of the temporary constructor. function Object(o) { function F() {} F.…

Commonalities • There’s a convention on how to name a method, which is to be considered the constructor of the class. • Classes inherit from other classes. • There’s access to the parent class (superclass) from within the child class. The function ta…

// the parent constructor function Parent(name) { this.name = name || 'Adam'; } // adding functionality to the prototype Parent.prototype.say = function () { return this.name; }; // empty child constructor function Child(name) {} inherit(Child, Paren…

Chaining Pattern - Call methods on an object one after the other without assigning the return values of the previous operations to variables and without having to split your calls on multiple lines. var obj = { value: 1, increment: function () { this…

Drawbacks of the namespacing pattern • Reliance on a single global variable to be the application’s global. In the namespacing pattern, there is no way to have two versions of the same application or library run on the same page, because they both ne…

MYAPP.namespace('MYAPP.utilities.array'); MYAPP.utilities.array = (function () { // dependencies var uobj = MYAPP.utilities.object, ulang = MYAPP.utilities.lang, // private properties array_string = "[object Array]", ops = Object.prototype.toStr…

All object members are public in JavaScript. var myobj = { myprop : 1, getProp : function() { return this.myprop; } }; console.log(myobj.myprop); // `myprop` is publicly accessible console.log(myobj.getProp()); // getProp() is public too The same is…

global namespace object // global object var MYAPP = {}; // constructors MYAPP.Parent = function() { }; MYAPP.Child = function() { }; // a variable MYAPP.some_var = 1; // an object container MYAPP.modules = {}; // nested objects MYAPP.modules.module1…

Function Application apply() takes two parameters: the first one is an object to bind to this inside of the function, the second is an array or arguments, which then becomes the array-like arguments object available inside the function. If the first…

Configuration Objects Passing a large number of parameters is not convenient. A better approach is to substitute all the parameters with only one and make it an object. var conf = { username: "batman", first: "Bruce", last: "Wayne…

Gets a length property containing the number of arguments the function expects: function func(a, b, c) {} console.log(func.length); var myFunc = function () { // serialize the arguments object as a JSON string and use that string as a key in your cac…

//对象是可变的键控集合, //"numbers, strings, booleans (true and false), null, and undefined" 不是对象的解释 The simple types of JavaScript are numbers, strings, booleans (true and false), null, and undefined. All other values are objects. Numbers, strings, and b…

In Java you could do something like: Person adam = new Person(); In JavaScript you would do: var adam = new Person(); JavaScript’s constructor invocation looks as if Person were a class, but it’s important to keep in mind that Person is still just a…

Advantage Avoid re-created instance method to this inside of the constructor. method() implementation The method() takes two parameters: • The name of the new method • The implementation of the method if (typeof Function.prototype.method !== "functio…

Public Static Members // constructor var Gadget = function (price) { this.price = price; }; // a static method Gadget.isShiny = function () { // this always works var msg = "you bet"; // Checking if the static method is called by instance. if (t…

It’s a good idea to declare the modules your code relies on at the top of your function or module. The declaration involves creating only a local variable and pointing to the desired module. var myFunction = function() { // dependencies var event = Y…

When you know that a certain condition will not change throughout the life of the program, it makes sense to test the condition only once. Browser sniffing (or feature detection) is a typical example. // BEFORE var utils = { addListener : function(el…

上一篇(JavaScript中你所不知道的Object(一))说到,Object对象有大量的内部属性,而其中多数和外部属性的操作有关.最后留了个悬念,就是Boolean.Date.Number.String.Function等有更多的内部属性,而它们分别是什么呢? 这些内部属性不能像Object的内部属性一样一言以蔽之,因为它们各有各的用处和特点.其中核心的部分自然是最特殊的对象,Function对象.我们先从简单的开始: [[PrimitiveValue]]: 值的类型是基础数据类型.所以所有…

Objective -C Object initialization 对象初始化 1.1 Allocating Objects  分配对象 Allocation is the process by which a new object is born. allocation 是新对象诞生的过程. Sending the alloc message to a class causes that class to allocate a chunk of memory large enough to…

Basic concept Values can be properties: primitives or other objects methods: functions User-defined native objects are mutable at any time. Object literal notation is ideal for this type of on-demand object creation. Even the simplest {} object alrea…

1.1 Pattern "theme of recurring events or objects… it can be a template or model which can be used to generate things" (http://en.wikipedia.org/wiki/Pattern). • Design patterns - Elements of Reusable Object-Oriented Software. • Coding patterns -…

写的很好,理解了很多,特此转发记录 转自:http://blog.csdn.net/tom_221x/archive/2010/02/22/5316675.aspx 在JavaScript中所有的对象都继承自Object原型,而Function又充当了对象的构造器,那么Funtion和Object到底有着什麽样的关系呢 ? 首先,一切都是对象. 由此可见,Object继承自己,Funtion继承自己,Object和Function互相是继承对方,也就是说Object和Function都既是函数也…

JavaScript中并没有直接提供对象复制(Object Clone)的方法.因此下面的代码中改变对象b的时候,也就改变了对象a. a = {k1:1, k2:2, k3:3}; b = a; b.k2 = 4; 如果只想改变b而保持a不变,就需要对对象a进行复制. 用jQuery进行对象复制   在可以使用jQuery的情况下,jQuery自带的extend方法可以用来实现对象的复制. a = {k1:1, k2:2, k3:3}; b = {}; $.extend(b,a);   自定义c…

The immediate function pattern is a syntax that enables you to execute a function as soon as it is defined. (function () { alert('watch out!'); }());  • You define a function using a function expression. (A function declaration won’t work.) • You add…