JavaScript基于对象去除数组重复项的方法

var toObject = function(arr){
    var obj = new Object(); //私有对象
    var j = arr.length;
    for(var i=0; i < j; +i+){
        obj[arr[i]] = true;
    }
    return obj;
}
var keys = function(obj){
    var arr = [];
    for(var attr in obj){
        if(obj.hasOwnPerpoty(attr)){
            arr.push(attr);
        }
    }
    return arr;
}
var uniq = function(arr){ //去除重复项
    return keys(toObject(newarr));
}