codewars--js--create phone number

Write a function that accepts an array of 10 integers (between 0 and 9), that returns a string of those numbers in the form of a phone number.

Example:

createPhoneNumber([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]) // => returns "(123) 456-7890"

The returned format must be correct in order to complete this challenge. 
Don't forget the space after the closing parentheses!

我的答案：

 function createPhoneNumber(numbers){

   //var a="(".concat(numbers);
   //a=a.replace(/,/g,"");
   var a=numbers.slice(0,3);
   a="(".concat(a).concat(") ");
   var b=numbers.slice(3,6);
   b=b.concat("-");
   var c=numbers.slice(6);
   var d=a.concat(b).concat(c);
   d=d.replace(/,/g,"");
   return d; 

 }

优秀答案：

 function createPhoneNumber(numbers){
   var format = "(xxx) xxx-xxxx";

   for(var i = ; i < numbers.length; i++)
   {
     format = format.replace('x', numbers[i]);
   }

   return format;
 }

 function createPhoneNumber(numbers){
   return numbers.join('').replace(/(...)(...)(.*)/, '($1) $2-$3');
 }