kostikovmu

function telephoneCheck(str) {
  const phoneRegxep = /^((\(\d{3}\))|((1\s|1)\(\d{3}\))|(\d{3})|(1\s\d{3}))(\s|-|)(\d{3})(\s|-)(\d{4})/

  const d10 = /^\d{10}$/

  return phoneRegxep.test(str) || d10.test(str);
}

// phone formats
// 555-555-5555

kostikovmu

function rot13Decode(str) {
  return [...str].map( el => {
    const code = el.charCodeAt(0)
    const newCode = code > 77 && code < 91 ? + code - 13 :
      code > 64 && code < 78 ? code + 13 : code
    return String.fromCharCode(newCode)
  }).join('');
}

kostikovmu

function convertToRoman(num) {
 const arr = num.toString().split('').map( el => +el).reverse();
 let res = ''
 const v10 = [
   'I', 'X', 'C', 'M'
 ]
 const v5 = [
   'V', 'L' , 'D'
 ]
 arr.forEach( (el, i) => {