phonePartsUSA.js JavaScript function to split a US phone number into its component parts

phonePartsUSA.js

function phonePartsUSA(phoneNumberInput) {

  const phoneNumber = ("" + phoneNumberInput).replace(/[^0-9]/g, "");

  if (phoneNumber.length != 10) throw new Error("phoneNumberInput must have 10 digits");  

  const areacode = phoneNumber.slice(0, 3);
  const prefix = phoneNumber.slice(3, 6);
  const exchange = phoneNumber.slice(6, 10);
  const dialnumber = prefix + exchange;
  const dashFormatted = [areacode, prefix, exchange].join('-');
  const parensDashFormatted = "(" + areacode + ") " + prefix + "-" + exchange;
  const parensDashFormattedNoSpace = "(" + areacode + ")" + prefix + "-" + exchange;

  const phoneNumberObject = {
    areacode: areacode,
    prefix: prefix,
    exchange: exchange,
    dialnumber: dialnumber,
    formatted: {
      dashes: dashFormatted,
      parensSpaceDash: parensDashFormatted,
      parensDash: parensDashFormattedNoSpace,
      numbersOnly: areacode + prefix + exchange
    }
  }

  return phoneNumberObject;
}


console.log(phonePartsUSA("(123) 456-7890").areacode)                
// "123"

console.log(phonePartsUSA(1234567890).dialnumber)
// "4567890"

console.log(phonePartsUSA("123.456.7890").formatted.parensSpaceDash)
// "(123) 456-7890"

console.log(phonePartsUSA("(123) 456-7890").formatted.numbersOnly)
// "1234567890"

console.log(phonePartsUSA("(123) 456-7890"))
// {object}

console.log(phonePartsUSA("123456"))
// error: "phoneNumberInput must have 10 digits"