javascript - Append +1 to phone number field value -

i need format phone number field correctly , have done.

i able use script add dashes in phone number how can add "+1" front of phone number when 10 numbers have been typed?

$('#tel').keyup(function(){     $(this).val($(this).val().replace(/(\d{3})\-?(\d{3})\-?(\d{4})/,'$1-$2-$3')) }); 

i first suggest replace keyup event input (which has ie 10+ support) if @ possible. next, should rework filter true numeric value first. work regex against that. in example replaced non-10-digit-numbers dash separated values, trimmed resulting trailing dashes, , replaced full 10-digit-value same value , +1 @ beginning.

$('#tel').on('input', function(){      var filteredvalue = this.value.replace('+1 ', '').match(/\d*/g).join('');      $(this).val(filteredvalue        .replace(/(\d{0,3})\-?(\d{0,3})\-?(\d{0,4}).*/,'$1-$2-$3')        .replace(/\-+$/, '')        .replace(/(\d{3})\-?(\d{3})\-?(\d{4})/,'+1 $1-$2-$3'))  });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>  <input id=tel>

here's simplified version closer original makes replacement @ end of having 10 digits.

$('#tel').on('input', function(){      var filteredvalue = this.value.replace('+1 ', '').match(/\d*/g).join('');      $(this).val(filteredvalue        .replace(/(\d{3})\-?(\d{3})\-?(\d{4}).*/,'+1 $1-$2-$3'))  });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>  <input id=tel>