Shijie Lu lushijie

## truthy.js
//undefined 与 null 返回false，其他返回true
function existy(x) {
    return x != null;
}

function truthy(x) {
    return (x !== false) && existy(x);
}

function doWhen(condtion, action) {

## curry.js
function Foo(x, y, z, w) {
    var args = arguments;
    if (args.length < Foo.length) {
        return function() {
            var oldArgs = Array.prototype.slice.call(args);
            var newArgs = oldArgs.concat(Array.prototype.slice.call(arguments));
            return args.callee.apply(null,newArgs);
        }
    } else {
        return x + y - z * w;

## reduce.js
//1.数组求和
var arr = [1,2,3,4];
var total = arr.reduce(function(pre, cur, index, arr){
    //接受四个参数：初始值（或者上一次回调函数的返回值），当前元素值，当前索引，调用 reduce 的数组
    //arr.reduce(callback,[initialValue])
    return pre + cur;
})
console.log(total)
//2.把二维数组转换为json键值对
var relArray = [

## onceWraper.js
function onceWraper(func){
    return function(){
        if(func){
            var ret = func.apply(this,arguments);
            func = null;
            return ret;
        }else{
            console.log('非第一次运行不再执行');
            return;
        }

## shareFunc.js
function shareFunc(func){
    //初始化函数运行过程中依赖的变量
    //之前一般的方式是声明全局变量,程序的阅读与理解难度增加，全局变量容易受干扰
    var varWraper ={
        a:0
    }
    return function(){
        var args = [].slice.apply(arguments);
        args.push(varWraper);
        var ret = func.apply(this,args);

## debounce&throttle.js
$.debounce = function(fn, time, ctx) {
    var ret = 0;
    if( typeof time !== 'number' ) {
      ctx = time;
      time =  50;
    }
    time = time || 50;
    return function() {
      var args = [].slice.apply(arguments);
      // 注意是ctx的问题

## Analytics.js
(function(i, s, o, g, r, a, m) {
	i['GoogleAnalyticsObject'] = r;
	i[r] = i[r] || function() {
		(i[r].q = i[r].q || []).push(arguments)
	}, i[r].l = 1 * new Date();
	a = s.createElement(o),
		m = s.getElementsByTagName(o)[0];
	a.async = 1;
	a.src = g;
	m.parentNode.insertBefore(a, m)

## declareAndCall.js
var func = (function f(a) {
    console.log(a);
    return f;
})('Hello World');

## doubleBitwise.js
Math.floor(4.9) === 4  //true
~~4.9 === 4  //true
(4.9 | 0) === 4 //true

## compareVerison.js
var versions= [{"version":"1.3.0-beta.2"},{"version":"1.3.0-beta.19"},{"version":"1.3.0-beta.18"},{"version":"1.3.0-beta.17"},{"version":"1.3.0-beta.16"},{"version":"1.3.0-beta.15"},{"version":"1.3.0-beta.14"},{"version":"1.3.0-beta.13"},{"version":"1.3.0-beta.12"},{"version":"1.3.0-beta.11"},{"version":"1.3.0-beta.10"},{"version":"1.3.0-beta.1"},{"version":"1.3.0"},{"version":"1.2.9"},{"version":"1.2.8"},{"version":"1.2.7"},{"version":"1.2.6"},{"version":"1.2.5"},{"version":"1.2.4"},{"version":"1.2.30"},{"version":"1.2.3"},{"version":"1.2.29"},{"version":"1.2.28"},{"version":"1.2.27"},{"version":"1.2.26"},{"version":"1.2.25"},{"version":"1.2.24"},{"version":"1.2.23"},{"version":"1.2.22"},{"version":"1.2.21"},{"version":"1.2.20"},{"version":"1.2.2"},{"version":"1.2.19"},{"version":"1.2.18"},{"version":"1.2.17"},{"version":"1.2.16"},{"version":"1.2.15"},{"version":"1.2.14"},{"version":"1.2.13"},{"version":"1.2.12"},{"version":"1.2.11"},{"version":"1.2.10"},{"version":"1.2.1"},{"version":"1.2.0rc3"},{"version":
	//undefined 与 null 返回false，其他返回true
	function existy(x) {
	return x != null;
	}

	function truthy(x) {
	return (x !== false) && existy(x);
	}

	function doWhen(condtion, action) {
	function Foo(x, y, z, w) {
	var args = arguments;
	if (args.length < Foo.length) {
	return function() {
	var oldArgs = Array.prototype.slice.call(args);
	var newArgs = oldArgs.concat(Array.prototype.slice.call(arguments));
	return args.callee.apply(null,newArgs);
	}
	} else {
	return x + y - z * w;
	//1.数组求和
	var arr = [1,2,3,4];
	var total = arr.reduce(function(pre, cur, index, arr){
	//接受四个参数：初始值（或者上一次回调函数的返回值），当前元素值，当前索引，调用 reduce 的数组
	//arr.reduce(callback,[initialValue])
	return pre + cur;
	})
	console.log(total)
	//2.把二维数组转换为json键值对
	var relArray = [
	function onceWraper(func){
	return function(){
	if(func){
	var ret = func.apply(this,arguments);
	func = null;
	return ret;
	}else{
	console.log('非第一次运行不再执行');
	return;
	}
	function shareFunc(func){
	//初始化函数运行过程中依赖的变量
	//之前一般的方式是声明全局变量,程序的阅读与理解难度增加，全局变量容易受干扰
	var varWraper ={
	a:0
	}
	return function(){
	var args = [].slice.apply(arguments);
	args.push(varWraper);
	var ret = func.apply(this,args);
	$.debounce = function(fn, time, ctx) {
	var ret = 0;
	if( typeof time !== 'number' ) {
	ctx = time;
	time = 50;
	}
	time = time \|\| 50;
	return function() {
	var args = [].slice.apply(arguments);
	// 注意是ctx的问题
	(function(i, s, o, g, r, a, m) {
	i['GoogleAnalyticsObject'] = r;
	i[r] = i[r] \|\| function() {
	(i[r].q = i[r].q \|\| []).push(arguments)
	}, i[r].l = 1 * new Date();
	a = s.createElement(o),
	m = s.getElementsByTagName(o)[0];
	a.async = 1;
	a.src = g;
	m.parentNode.insertBefore(a, m)
	var func = (function f(a) {
	console.log(a);
	return f;
	})('Hello World');
	Math.floor(4.9) === 4 //true
	~~4.9 === 4 //true
	(4.9 \| 0) === 4 //true