JAVASCRIPT

javascript function to format phone number

function formatPhoneNumber(phoneNumberString) {
  var cleaned = ('' + phoneNumberString).replace(/D/g, '')
  var match = cleaned.match(/^(d{3})(d{3})(d{4})$/)
  if (match) {
    return '(' + match[1] + ') ' + match[2] + '-' + match[3]
  }
  return null
}

how to apply phone number formatting to html with javascript

// A function to format text to look like a phone number
function phoneFormat(input){
        // Strip all characters from the input except digits
        input = input.replace(/D/g,'');
        
        // Trim the remaining input to ten characters, to preserve phone number format
        input = input.substring(0,10);

        // Based upon the length of the string, we add formatting as necessary
        var size = input.length;
        if(size == 0){
                input = input;
        }else if(size < 4){
                input = '('+input;
        }else if(size < 7){
                input = '('+input.substring(0,3)+') '+input.substring(3,6);
        }else{
                input = '('+input.substring(0,3)+') '+input.substring(3,6)+' - '+input.substring(6,10);
        }
        return input; 
}

format phone number javascript

^(([0-9]{3})|[0-9]{3}-)[0-9]{3}-[0-9]{4}$