JavaScript数组去重的3种方法和代码实例
数组去重的方法有很多，到底哪种是最理想的，自己不清楚。于是自己测试了下数组去重的效果和性能。测试十万个数据，代码和所耗大概时间如下。
到底采用哪种方法，根据实际情况而定吧。
/*方法一：1,'1'会被认为是相同的;所有hash对象,如：{x;1}，{y:1}会被认为是相同的//10ms*/
Array.prototype.unique=function(){
varnewArr=[],obj={};
for(vari=0,len=this.length;i<len;i++){
if(!obj[this[i]]){
newArr.push(this[i]);
obj[this[i]]=true;
}
}
returnnewArr;
}
/*方法一改进版：所有hash对象,如：{x;1}，{y:1}会被认为是相同的//30ms*/
Array.prototype.unique=function(){
varnewArr=[],obj={};
for(vari=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];
}
}
returnnewArr;
}
/*方法二：去重结果最好，但耗性能//250ms*/
Array.prototype.unique=function(){
varnewArr=this.concat();
for(vari=0,len=newArr.length;i<len;i++){
for(varj=i+1,len=newArr.length;j<len;j++){
//注意===
if(newArr[i]===newArr[j]){
newArr.splice(j,1);
j--;
}
}
}
returnnewArr;
}
/*方法三：不能去重hash对象//25ms*/
Array.prototype.unique=function(){
varnewArr=[];//一个新的临时数组
for(vari=0,len=this.length;i<len;i++){
if(newArr.indexOf(this[i])==-1){//如果当前数组的第i已经保存进了临时数组，那么跳过,否则把当前项push到临时数组里面
newArr.push(this[i]);
}
}
returnnewArr;
}
vararr0=[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","火柴人技巧格斗","超音速战场","小小辛打砖块","火柴人技巧格斗","加菲猫超人","小小辛打砖块","卑鄙的我2","电流导线","飞天手推车","神D秘人物","火柴人S技巧格斗","超音SD速战场","小小SD辛打砖块","火柴人SD技巧格斗","加菲S猫超人","小小DF辛打砖块","卑鄙的FS我2","电D流导线","飞天SD手推车","神秘SD人物","火柴人技D巧格斗","超音ASD速战场","小小辛打SAD砖块","火柴人技SD巧格斗","加菲FDS猫超人","小小辛打SDF砖块","卑鄙SDF的我2","电流SDF导线","飞天手DF推车","神秘SD人物","火柴人技AS巧格斗","超音速战FS场","小小辛SDF打砖块","火柴人SDF技巧格斗","加菲SD猫超人",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巧格斗","超音速sd战场","小小辛sd打砖块","火柴人技巧gw格斗","加菲猫ui超人","小小辛yi打砖块","卑鄙的yi我2","电流yt导线","飞天手ytui推车","神Dyu秘人物","火yui柴人S技yui巧格斗","超音SDyu速战场","小小SD辛打砖uyi块","火柴yui人SD技巧格斗","加yui菲S猫超人","小小DF辛打砖ui块","卑鄙uyi的FS我2","电D流导yui线","飞天SD手推uyi车","神i秘SD人物","火柴人技Dhk巧格斗","超音ASD速战hk场","小小辛打SAhkD砖块","火柴人技SD巧ghk格斗","加菲FDS猫k超人","小小辛打SDF砖ytui块","卑鄙SDF的yui我2","电流SDyuF导线","飞天手yuiDF推车","神iy秘SD人hk物","火柴uyi人技AS巧格hk斗","超音hg速战FS场","小小辛SDF打砖hjk块","火柴人SDF技hj巧格斗","加菲SDhk猫超人"];
/*十万个随机数据*/
vararr=[],num;
for(vari=0;i<100000;i++){
num=Math.floor(Math.random()*50);
arr.push(arr0[num]);
}
vart1=newDate().getTime();console.log(t1);//开始时间
arr.unique();//去重
vart2=newDate().getTime();console.log(t2);//结束时间
console.log(t2-t1);