Array.prototype.unique = function(){
 var result = [];
 this.forEach(function(v){
  if(result.indexOf(v) < 0){
   result.push(v);
  }
 });
 return result;
}

Array.prototype.unique = function(){
 var result = [],hash = {};
 this.forEach(function(v){
  if(!hash[v]){
   hash[v] = true;
   result.push(v);
  }
 });
 return result;
}

Array.prototype.unique = function(){
 var result = [],hash = {};
 this.forEach(function(v){
  var type = typeof(v); //获取元素类型
  hash[v] || (hash[v] = new Array());
  if(hash[v].indexOf(type) < 0){
   hash[v].push(type); //存储类型
   result.push(v);
  }
 });
 return result;
}

Array.prototype.unique = function(){
 var result = [this[0]];
 this.sort();
 this.forEach(function(v){
  v != result[result.length - 1] && result.push(v); //仅与result最后一个元素比较
 });
}

function quickSort(arr){
 qSort(arr,0,arr.length - 1);
}
function qSort(arr,low,high){
 if(low < high){
  var partKey = partition(arr,low,high);
  qSort(arr,low, partKey - 1);
  qSort(arr,partKey + 1,high);
 }
}
function partition(arr,low,high){
 var key = arr[low]; //使用第一个元素作为分类依据
 while(low < high){
  while(low < high && arr[high] >= arr[key])
   high--;
  arr[low] = arr[high];
  while(low < high && arr[low] <= arr[key])
   low++;
  arr[high] = arr[low];
 }
 arr[low] = key;
 return low;
}

function quickSort(arr){
 if(arr.length <= 1) return arr;
 var index = Math.floor(arr.length/2);
 var key = arr.splice(index,1)[0];
 var left = [],right = [];
 arr.forEach(function(v){
  v <= key ? left.push(v) : right.push(v);
 });
 return quickSort(left).concat([key],quickSort(right));
}

var scope = "global";
function myFunc(){
 console.log(scope); 
 var scope = "local";
}

var scope = "global";
function myFunc(){
 var scope;
 console.log(scope);
 scope = "local";
}

function outFunc(){
 var name = "Vicfeel";
 function inFunc(){
  console.log(name);
 }
 return inFunc;
}
inFunc(); //控制台显示"Vicfeel"

function User(){
  this.name = "Vicfeel"; //共有属性
  var age = 23; //私有属性
  this.sayAge:function(){
   console.log("my age is " + age); 
  }
 }
 var user = new User();
 console.log(user.name); //"Vicfeel"
 console.log(user.age); //"undefined"
 user.sayAge(); //"my age is 23"

function User(){
this.name = "Vicfeel";
this.age = 23;
}

var user = new User();

 function User(){
  //this = {}; 
  //this.constructor = User；
  this.name = "Vicfeel";
  this.age = 23;
  //return this;
 }
 
 var user = new User();

<ul id='list'></ul>
 var count = 100;
 var ulList = document.getElementById("list");
 //动态构建节点
 for(var i = count;i--;){
  var liDom = document.createElement('li');
  ulList.appendChild(liDom);
 }
 //绑定点击事件
 var liNode = ulList.getElementByTagName("li");
 for(var i=0, l = liNodes.length; i < l; i++){
  liNode[i].onClick = function(){
   //li点击事件
  }
 } 

 var count = 100;
 var ulList = document.getElementById("list");
 //动态构建节点
 for(var i = count;i--;){
  var liDom = document.createElement('li');
  ulList.appendChild(liDom);
 }
 //绑定点击事件
 var liNode = ulList.getElementByTagName("li");
 liNode.onClick = function(e){
  if(e.target && e.target.nodeName.toUpperCase == "LI") {
   // li点击事件
  }
 }