数组去重

var ary=[12,23,67,23,6,7,8,12]
var obj={};
for(var i=0;i<ary.length;i++){
    var cur=ary[i];
    if(obj[cur]===cur){
        ary[i]=ary[ary.length-1];
        i--;
        ary.length--;
    }
    obj[cur]=cur;
}