Bootstrap Registration Form With Validation Codepen Code Example

Example: form validation javascript bootstrap

<script>           // Example starter JavaScript for disabling form submissions if there are invalid fields           (function() {             'use strict';             window.addEventListener('load', function() {               // Fetch all the forms we want to apply custom Bootstrap validation styles to               var forms = document.getElementsByClassName('needs-validation');               // Loop over them and prevent submission               var validation = Array.prototype.filter.call(forms, function(form) {                 form.addEventListener('submit', function(event) {                   if (form.checkValidity() === false) {                     event.preventDefault();                     event.stopPropagation();                   }                   form.classList.add('was-validated');                 }, false);               });             }, false);           })();           </script>