JavaScript數組去重的3種方法和代碼執行個體_javascript技巧

數組去重的方法有很多，到底哪種是最理想的，自己不清楚。於是自己測試了下數組去重的效果和效能。測試十萬個資料，代碼和所耗大概時間如下。

　　到底採用哪種方法，根據實際情況而定吧。

/*方法一： 1,'1' 會被認為是相同的; 所有hash對象,如：{x;1}，{y:1}會被認為是相同的 //10ms */Array.prototype.unique=function(){  var newArr=[],obj={};  for(var i=0,len=this.length;i<len;i++){    if(!obj[this[i]]){       newArr.push(this[i]);      obj[this[i]]=true;    }  }  return newArr;}/*方法一改進版：所有hash對象,如：{x;1}，{y:1}會被認為是相同的 //30ms*/Array.prototype.unique=function(){  var newArr=[],obj={};  for(var i=0,len=this.length;i<len;i++){    if(!obj[typeof(this[i])+this[i]]){       newArr.push(this[i]);      obj[typeof(this[i])+this[i]]=this[i];    }  }  return newArr;}/*方法二： 去重結果最好，但耗效能   //250ms*/Array.prototype.unique=function(){  var newArr=this.concat();  for(var i=0,len=newArr.length;i<len;i++) {    for(var j=i+1,len=newArr.length;j<len;j++) {      //注意 ===      if(newArr[i]===newArr[j]) {        newArr.splice(j,1);        j--;      }    }  }  return newArr;}/*方法三： 不能去重hash對象 //25ms */Array.prototype.unique = function(){  var newArr = []; //一個新的臨時數組  for(var i = 0,len=this.length; i < len; i++){        if (newArr.indexOf(this[i]) == -1){  //如果當前數組的第i已經儲存進了臨時數組，那麼跳過,否則把當前項push到臨時數組裡面      newArr.push(this[i]);    }  }  return newArr;}var arr0=[11,21,221,13,24,"134","1",{x:1,y:1},{name:"pobaby",age:"12",hobby:"football"},{name:"pobaby1",age:"121",hobby:"football1"},{x:134},{y:132},{x:143},{y:3421},"神秘人物", "火柴人技巧格鬥", "超音速戰場", "小小辛打磚塊", "火柴人技巧格鬥", "加菲貓超人", "小小辛打磚塊", "卑鄙的我2", "電流導線", "飛天手推車","神D秘人物", "火柴人S技巧格鬥", "超音SD速戰場", "小小SD辛打磚塊", "火柴人SD技巧格鬥", "加菲S貓超人", "小小DF辛打磚塊", "卑鄙的FS我2", "電D流導線", "飛天SD手推車","神秘SD人物", "火柴人技D巧格鬥", "超音ASD速戰場", "小小辛打SAD磚塊", "火柴人技SD巧格鬥", "加菲FDS貓超人", "小小辛打SDF磚塊", "卑鄙SDF的我2", "電流SDF導線", "飛天手DF推車","神秘SD人物", "火柴人技AS巧格鬥", "超音速戰FS場", "小小辛SDF打磚塊", "火柴人SDF技巧格鬥", "加菲SD貓超人",113,231,2221,123,234,"1334","21",{x:13,y:132},{name:"pobaby2",age:"122",hobby:"football2"},{name:"pobaby13",age:"1231",hobby:"football41"},{x:13544},{y:1352},{x:14543},{y:34521},"神秘人sd物", "火柴人技sd巧格鬥", "超音速sd戰場", "小小辛sd打磚塊", "火柴人技巧gw格鬥", "加菲貓ui超人", "小小辛yi打磚塊", "卑鄙的yi我2", "電流yt導線", "飛天手ytui推車","神Dyu秘人物", "火yui柴人S技yui巧格鬥", "超音SDyu速戰場", "小小SD辛打磚uyi塊", "火柴yui人SD技巧格鬥", "加yui菲S貓超人", "小小DF辛打磚ui塊", "卑鄙uyi的FS我2", "電D流導yui線", "飛天SD手推uyi車","神i秘SD人物", "火柴人技Dhk巧格鬥", "超音ASD速戰hk場", "小小辛打SAhkD磚塊", "火柴人技SD巧ghk格鬥", "加菲FDS貓k超人", "小小辛打SDF磚ytui塊", "卑鄙SDF的yui我2", "電流SDyuF導線", "飛天手yuiDF推車","神iy秘SD人hk物", "火柴uyi人技AS巧格hk鬥", "超音hg速戰FS場", "小小辛SDF打磚hjk塊", "火柴人SDF技hj巧格鬥", "加菲SDhk貓超人" ];/*十萬個隨機資料*/var arr=[],num;for(var i = 0; i < 100000; i++){  num=Math.floor(Math.random()*50);  arr.push(arr0[num]);}var t1= new Date().getTime(); console.log(t1); //開始時間arr.unique(); //去重var t2 = new Date().getTime(); console.log(t2); //結束時間console.log(t2-t1);