JSON: JavaScript Object Notation {"name": "value", "some": [1, 2, 3]}  The only syntax difference between JSON and the object literal is that property names need to be wrapped in quotes to be valid JSON. In object literals th…

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…

javascript eval函数解析json数据时为什么 加上圆括号?为什么要 eval这里要添加 “("("+data+")");//”呢?   原因在于:eval本身的问题. 由于json是以”{}”的方式来开始以及结束的,在JS中,它会被当成一个语句块来处理,所以必须强制性的将它转换成一种表达式. 加上圆括号的目的是迫使eval函数在处理JavaScript代码的时候强制将括号内的表达式(expression)转化为对象,而不是作为语句(statement)…

JSON 对象包含了两个方法,一是解析 JavaScript Object Notation (JSON),二是将值转换为 JSON.这个对象本身不能被调用或者作为构造函数,除了它的这两个方法属性外 JSON 对象本身并没有什么有用的功能 JSON.parse() 方法将一个 JSON字符串解析成一个javascript值. JSON.stringify() 方法可以将任意的 JavaScript 值序列化成 JSON 字符串.  …

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…