JavaScript数组去重

Array.prototype.unique = function () {
	var arr = [];
		temp = {};
		len = this.length;
	for(var i = 0; i < len; i++)
	{
		if(!temp[this[i]]){
			temp[this[i]] = 'flag'
			arr.push(this[i]);
		}
	}
	return arr;
}