CODE EXAMPLE FOR JAVASCRIPT

javascript credit card validation

// You will need various ragex for difference card validation
// eg
function cardnumber(inputtxt)
{
  var cardno = /^(?:4[0-9]{12}(?:[0-9]{3})?)$/;
  if(inputtxt.value.match(cardno))
        {
      return true;
        }
      else
        {
        alert("Not a valid Visa credit card number!");
        return false;
        }
}
// Or you can use card-validator npm package
// npm i card-validator

var valid = require("card-validator");

var numberValidation = valid.number("4111");

if (!numberValidation.isPotentiallyValid) {
  renderInvalidCardNumber();
}

if (numberValidation.card) {
  console.log(numberValidation.card.type); // 'visa'
}