Challenge 1 of FreeCode Camp Advanced Algorithm Challenges

fcc_validate_us_telephone_numbers.js

// freecodecamp
// advanced algorithm scripting
// validate us telephone numbers



function telephoneCheck(str) {
  var regex = /^1?\s?((\(\d{3}\))|\d{3})(\s|\-)?\d{3}(\s|\-)?(\d{4})$/;
  return regex.test(str);
}



console.log(telephoneCheck("555-555-5555")); //true
console.log(telehphoneCheck("1 555 555 5555")); //true
console.log(telehphoneCheck("1 555-555-5555")); //true
console.log(telehphoneCheck("1 (555) 555-5555")); //true
console.log(telehphoneCheck("(555)555-5555")); //true
console.log(telehphoneCheck("555)-555-5555")); //false