Validate phone number with JavaScript

Question

I found this code in some website, and it works perfectly. It validates that the phone number is in one of these formats:
(123) 456-7890 or 123-

Answer 1

/^\+?1?\s*?\(?\d{3}(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$/

Although this post is an old but want to leave my contribuition. these are accepted: 5555555555 555-555-5555 (555)555-5555 1(555)555-5555 1 555 555 5555 1 555-555-5555 1 (555) 555-5555

these are not accepted:

555-5555 -> to accept this use: ^\+?1?\s*?\(?(\d{3})?(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$

5555555 -> to accept this use: ^\+?1?\s*?\(?(\d{3})?(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$

1 555)555-5555 123**&!!asdf# 55555555 (6505552368) 2 (757) 622-7382 0 (757) 622-7382 -1 (757) 622-7382 2 757 622-7382 10 (757) 622-7382 27576227382 (275)76227382 2(757)6227382 2(757)622-7382 (555)5(55?)-5555

this is the code I used:

function telephoneCheck(str) {
  var patt = new RegExp(/^\+?1?\s*?\(?\d{3}(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$/);
  return patt.test(str);
}

telephoneCheck("+1 555-555-5555");

Answer 2

Validate phone number + return formatted data

function validTel(str){
  str = str.replace(/[^0-9]/g, '');
  var l = str.length;
  if(l<10) return ['error', 'Tel number length < 10'];
  
  var tel = '', num = str.substr(-7),
      code = str.substr(-10, 3),
      coCode = '';
  if(l>10) {
    coCode = '+' + str.substr(0, (l-10) );
  }
  tel = coCode +' ('+ code +') '+ num;
  
  return ['succes', tel];
}

console.log(validTel('+1 [223] 123.45.67'));