javascript - Format credit card number -

how format , validate credit card number spaces between each 4 digit while typing:

eg: 4464 6846 4354 3564 

i have tried:

$('.creditno').keyup(function() {     cc = $(this).val().split("-").join("");      cc = cc.match(new regexp('.{1,4}$|.{1,4}', 'g')).join("-");      $(this).val(cc);  }); 

please help

try this:

function cc_format(value) {     var v = value.replace(/\s+/g, '').replace(/[^0-9]/gi, '')     var matches = v.match(/\d{4,16}/g);     var match = matches && matches[0] || ''     var parts = []      (i=0, len=match.length; i<len; i+=4) {         parts.push(match.substring(i, i+4))     }      if (parts.length) {         return parts.join(' ')     } else {         return value     } } 

note: check detailed information https://www.peterbe.com/plog/cc-formatter.

to restrict user enter number only:

javascript way

<input type="text" id="txt_cardnumber" name="txt_cardnumber" onkeypress="return checkdigit(event)">  function checkdigit(event) {     var code = (event.which) ? event.which : event.keycode;      if ((code < 48 || code > 57) && (code > 31)) {         return false;     }      return true; } 

or

function checkdigit() {     var allowedchars = "0123456789";     var entryval = document.getelementbyid('txt_cardnumber').value();     var flag;      for(var i=0; i<entryval.length; i++){                flag = false;          for(var j=0; j<allowedchars.length; j++){             if(entryval.charat(i) == allowedchars.charat(j)) {                 flag = true;              }         }          if(flag == false) {              entryval = entryval.replace(entryval.charat(i),""); i--;          }     }      return true; } 

html5 way

<input type="text" id="txt_cardnumber" name="txt_cardnumber" pattern="[0-9.]+"> <input type="number" id="txt_cardnumber" name="txt_cardnumber"> 

jquery way

$("#txt_cardnumber").keypress(function (e) {     if ((e.which < 48 || e.which > 57) && (e.which !== 8) && (e.which !== 0)) {         return false;     }      return true; }); 

note: please check here more information various key code.