Array.prototype.unique1 = function(){    var n = [];     for(var i = 0; i < this.length; i++)     {        if (n.indexOf(this[i]) == -1) n.push(this[i]);    }    return n;}Array.prototype.unique2 = function(){    var n = {},r=[];    for(var i = 0; i < this.length; i++)     {        if (!n[this[i]])         {            n[this[i]] = true;             r.push(this[i]);         }    }    return r;}Array.prototype.unique3 = function(){    var n = [this[0]];     for(var i = 1; i < this.length; i++)     {        if (this.indexOf(this[i]) == i) n.push(this[i]);    }    return n;}Array.prototype.unique4 = function(){    this.sort();    var re=[this[0]];    for(var i = 1; i < this.length; i++)    {        if( this[i] !== re[re.length-1])        {            re.push(this[i]);         }    }    return re;} Array.prototype.unique5 = function(){    var self = this;    var _a = this.concat().sort();    _a.sort(function(a,b){        if(a == b){            var n = self.indexOf(a);            self.splice(n,1);        }    });    return self;};Array.prototype.unique6 = function(){    return this.reduce(function(p, c)    {        if (p.indexOf(c) < 0) p.push(c);        return p;    }, []); };