script.js

var $jscomp = $jscomp || {};
$jscomp.scope = {};
$jscomp.arrayIteratorImpl = function(a) {
  var b = 0;
  return function() {
    return b < a.length ? {done:!1, value:a[b++]} : {done:!0};
  };
};
$jscomp.arrayIterator = function(a) {
  return {next:$jscomp.arrayIteratorImpl(a)};
};
$jscomp.makeIterator = function(a) {
  var b = "undefined" != typeof Symbol && Symbol.iterator && a[Symbol.iterator];
  if (b) {
    return b.call(a);
  }
  if ("number" == typeof a.length) {
    return $jscomp.arrayIterator(a);
  }
  throw Error(String(a) + " is not an iterable or ArrayLike");
};
function restrictInput(a) {
  a.value = a.value.replace(/[^0-9]/g, "").slice(0, 16);
}
function validateCreditCard(a) {
  a = a.replace(/\D/g, "");
  var b = getCardNetwork(a);
  return b && a.length == b.length && luhnCheck(a) ? !0 : !1;
}
function getCardNetwork(a) {
  for (var b = $jscomp.makeIterator([{pattern:/^\b4\d{15}\b/, name:"Visa", length:16}, {pattern:/^\b5[1-5]\d{14}\b/, name:"MasterCard", length:16}, {pattern:/^\b3[47]\d{13}\b/, name:"American Express", length:15}, {pattern:/^\b30[0-5]\d{11}\b/, name:"Diners Club", length:14}, {pattern:/^\b35[3-8]\d{13}\b/, name:"JCB", length:16}, {pattern:/^\b5[0678]\d{14,17}\b/, name:"Maestro", length:16}, {pattern:/^\b6011\d{12}\b/, name:"Discover", length:16}]), c = b.next(); !c.done; c = b.next()) {
    if (c = c.value, c.pattern.test(a)) {
      return {name:c.name, length:c.length};
    }
  }
  return null;
}
function luhnCheck(a) {
  for (var b = 0, c = !1, e = a.length - 1; 0 <= e; e--) {
    var d = parseInt(a.charAt(e));
    c && (d *= 2, 9 < d && (d -= 9));
    b += d;
    c = !c;
  }
  return 0 === b % 10;
}
function checkCC() {
  event.preventDefault();
  var a = document.querySelector("#cc"), b = document.querySelector("#result"), c = getCardNetwork(a.value);
  a = validateCreditCard(a.value);
  b.textContent = a ? "Credit card is valid. (" + c.name + ")" : "Credit card is invalid.";
  b.style.color = a ? "#4CAF50" : "#FF5733";
  return a;
};