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querystring参数小利器
querystring.stringify({name:‘lqc‘,course:[‘jade‘,‘node‘],from:‘‘})
//输出‘name=lqc&course=jade&course=node&from=‘
querystring.stringify({name:‘lqc‘,course:[‘jade‘,‘node‘],from:‘‘},‘,‘)
//输出‘name=lqc,course=jade,course=node,from=‘
querystring.stringify({name:‘lqc‘,course:[‘jade‘,‘node‘],from:‘‘},‘,‘,‘:‘)
//输出‘name:lqc,course:jade,course:node,from:‘
//反序列化，解析url的querystring字符串
querystring.parse(‘name=lqc&course=jade&course=node&from=‘)
//输出{ name: ‘lqc‘, course: [ ‘jade‘, ‘node‘ ], from: ‘‘ }
//转义：
querystring.escape(‘哈哈‘)
//输出‘%E5%93%88%E5%93%88‘
//反转义：
querystring.unescape(‘%E5%93%88%E5%93%88‘)
//输出‘哈哈‘
查看chrome浏览器的缓存
输入网址：chrome://net-internals/#dns
HTTP知识填坑：
状态码：status code
200
400
401
403
404
500
503
HTTP模块
HTTP事件回调
1.回调（把函数作为参数传递进去function add(callback) {console.log(callback)}function callback() {return
‘I am callback‘;}add(callback());）
function add(callback) {var value = callback(); console.log(‘Excuse me, ‘ + value)}
function callback() {return‘I am callback‘;}
add(callback);
callback.js文件：
1 /** 2 * 回调 3 * */ 4 function learn(something){ 5 console.log(something); 6 } 7 8 function we(callback, something) { 9 something += ‘ is cool‘; 10 callback(something); 11 } 12 13 we(learn, ‘Nodejs‘);
//命令行执行此文件
node callback
1 //传递一个匿名函数 2 we(function (something) { 3 console.log(something); 4 }, ‘JavaScript‘);
2.同步/异步
1 var c = 0; 2 3 function printIt() { 4 console.log(c); 5 } 6 7 function plus() { 8 //延迟1s 9 setTimeout(function () { 10 c += 1; 11 }, 1000); 12 } 13 14 plus(); 15 printIt();//结果为0
/*************************************************************/
//异步执行
1 var c = 0; 2 3 function printIt() { 4 console.log(c); 5 } 6 7 function plus(callback) { 8 //延迟1s 9 setTimeout(function () { 10 c += 1; 11 callback(); 12 }, 1000); 13 } 14 15 plus(printIt);
3.I/O
4.单线程/多线程
5.阻塞/非阻塞
6.事件
7.事件驱动
8.基于事件驱动的回调
9.事件循环
HTTP源码解读
作用域
1 ar globalVariable = ‘This is global variable‘; 2 3 function globalFunction () { 4 //局部变量 5 var localVariable = ‘This is local variable‘; 6 console.log(‘Visit global/local variable‘); 7 console.log(globalVariable); 8 console.log(localVariable); 9 10 globalVariable = ‘This is changed variable‘; 11 console.log(globalVariable); 12 13 function localFunction () { 14 var innerLocalVariable = ‘This is inner local variable‘; 15 console.log(‘Visit local function‘); 16 } 17 18 localFunction(); 19 } 20 21 globalFunction();
上下文
1 //声明一个对象变量 2 var pets = { 3 words: ‘...‘, 4 name: ‘ErBao‘, 5 kind: ‘rabbit‘, 6 speak: function () { 7 console.log(this.words); // ... 8 console.log(this === pets); // true 9 } 10 }; 11 12 pets.speak();
/*************************************/
1 function pets(words) { 2 this.words = words; 3 4 console.log(this.words); 5 console.log(this); //这里的this并不是pets，而是顶层的global对象 6 console.log(this === global); // true 7 } 8 9 pets(‘...‘);
this上下文对象是谁取决于函数的调用方式：1.直接调用(this表示全局对象) 2.实例化对象调用(this表示实例化的那个对象)
/*********************************/
1 function Pets(words) { 2 this.words = words; 3 this.speak = function () { 4 console.log(this.words); 5 console.log(this); 6 }; 7 console.log(this); 8 9 /** 10 Pets { words: ‘ErBao‘, speak: [Function] } 11 ErBao 12 Pets { words: ‘ErBao‘, speak: [Function] }*/ 13 } 14 15 //定义一个实例对象 16 var rabbit = new Pets(‘ErBao‘); 17 rabbit.speak();
/***********************************************/
call()，apply()
1 var pets = { 2 words: ‘...‘, 3 speak: function (say) { 4 console.log(say + this.words); 5 } 6 }; 7 8 //pets.speak(‘Speak ‘); 9 10 var dog = { 11 words: ‘wang‘ 12 }; 13 14 //call()方法实现JavaScript继承，改变执行上下文 15 //父对象.父对象的方法.call(子对象, 父对象方法的参数值),父对象的方法继承给子对象 16 //pets对象转换为dog对象，同时调用pets对象的方法 17 pets.speak.call(dog, ‘Speak ‘); // Speak wang
/***********************************************/
call、apply实现继承
//定义一个构造函数
1 //定义一个构造函数 2 function Pets(words) { 3 this.words = words; 4 5 this.speak = function () { 6 console.log(this.words); 7 }; 8 } 9 10 function Dog(words) { 11 Pets.call(this, words); 12 //Pets.apply(this, []); 13 } 14 15 var dog = new Dog(‘HuaHua‘); 16 dog.speak(); //HuaHua
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原文地址：http://www.cnblogs.com/lqcdsns/p/5349496.html
