PhoneNumber Formatter using Constructor functions JavaScript

March 17, 2022

I’m learning JavaScript, and I have this problem where I have to convert an array of numbers [6, 5, 0, 8, 3, 5, 9, 1, 7, 2] and

return as a string in this format: (650) 835-9172. using all the functions in this structure

function PhoneNumberFormatter(numbers) {
  this.numbers = numbers;
}

PhoneNumberFormatter.prototype.render = function() {
  var string = '';
  string = getAreaCode()+getExchangeCode()+"-"+getLineNumber()    //I did this
 
  return string;
};

PhoneNumberFormatter.prototype.getAreaCode = function() {
 let areaCode = this.numbers.slice(0,3);            //I did this
 return parenthesize(areaCode)                      //I did this

};

PhoneNumberFormatter.prototype.getExchangeCode = function() {
  return this.numbers.slice(3,6);     //I did this
 
};

PhoneNumberFormatter.prototype.getLineNumber = function() {
  return this.numbers.slice(6,10);     //I did this
};

PhoneNumberFormatter.prototype.parenthesize = function(string) {
  return '(' + string + ')';
};

PhoneNumberFormatter.prototype.slice = function(start, end) {
  return this.numbers.slice(start, end).join('');
};

Some help please?

>Solution :

you have forgot to use this keyword for the functions prototype methods. In each prototype method you have taken the sliced elements as strings without joining the elements.

Here is your code:-

function PhoneNumberFormatter(numbers) {
  this.numbers = numbers;
}

PhoneNumberFormatter.prototype.render = function() {
  var string = '';
  string = this.getAreaCode()+this.getExchangeCode()+"-"+this.getLineNumber()    //I did this
 
  return string;
};

PhoneNumberFormatter.prototype.getAreaCode = function() {
 let areaCode = this.slice(0,3);//I did this
 return this.parenthesize(areaCode)                      //I did this

};

PhoneNumberFormatter.prototype.getExchangeCode = function() {
  return this.slice(3,6);     //I did this
 
};

PhoneNumberFormatter.prototype.getLineNumber = function() {
  return this.slice(6,10);     //I did this
};

PhoneNumberFormatter.prototype.parenthesize = function(string) {
  return '(' + string + ')';
};

PhoneNumberFormatter.prototype.slice = function(start, end) {
  return this.numbers.slice(start, end).join('');
};

console.log(new PhoneNumberFormatter([6, 5, 0, 8, 3, 5, 9, 1, 7, 2]).render())