Как перенести каждый элемент массива на новою строчку?

    function Team(name) { 
        this.name = name; 
        this.letters = []; 
    } 
    Team.prototype.addLetter = function (...letters) { 
    for (var i=0; i<letters.length; i++) 
         this.letters.push(letters[i]); 
    }; 
    Team.prototype.toString = function () { 
      var res = "Name of team - " + this.name +  '\n' +"ltters :\n"; 
        
      for (var i=0; i<this.letters.length; i++) 
        res += this.letters[i]+"\n"; 
      return  res; 
    }; 
         
    
    var a = 's'; 
    b='g'; 
    v='d'; 
    var team1 =  new Team('letters'); 
    team1.addLetter(a,b,v); 
    console.log(team1.toString());