=============== HTML =============== <form class="needs-validation" novalidate action="javascript:void(0);"><div class="form-row"><div class="col-md-4 mb-4"><label for="validationCustom01">First name</label><input type="text" class="form-control" id="validationCustom01" placeholder="First name" value="Shaun" required><div class="valid-feedback">Looks good!</div></div><div class="col-md-4 mb-4"><label for="validationCustom02">Last name</label><input type="text" class="form-control" id="validationCustom02" placeholder="Last name" value="Park" required><div class="valid-feedback">Looks good!</div></div><div class="col-md-4 mb-4"><label for="validationCustomUsername">Username</label><div class="input-group"><div class="input-group-prepend"><span class="input-group-text" id="inputGroupPrepend">@</span></div><input type="text" class="form-control" id="validationCustomUsername" placeholder="Username" aria-describedby="inputGroupPrepend" required><div class="invalid-feedback">Please choose a username. </div></div></div></div><div class="form-row"><div class="col-md-6 mb-4"><label for="validationCustom03">City</label><input type="text" class="form-control" id="validationCustom03" placeholder="City" required><div class="invalid-feedback">Please provide a valid city. </div></div><div class="col-md-3 mb-4"><label for="validationCustom04">State</label><input type="text" class="form-control" id="validationCustom04" placeholder="State" required><div class="invalid-feedback">Please provide a valid state. </div></div><div class="col-md-3 mb-4"><label for="validationCustom05">Zip</label><input type="text" class="form-control" id="validationCustom05" placeholder="Zip" required><div class="invalid-feedback">Please provide a valid zip. </div></div></div><div class="form-group mb-4"><div class="form-check pl-0"><div class="custom-control custom-checkbox checkbox-success"><input type="checkbox" class="custom-control-input" id="invalidCheck" required><label class="custom-control-label" for="invalidCheck">Agree to terms and conditions</label><div class="invalid-feedback">You must agree before submitting. </div></div></div></div><button class="btn btn-primary mt-3" type="submit">Submit form</button></form>

=============== Javascript =============== 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);

=============== HTML =============== <form><div class="form-row"><div class="col-md-4 mb-4"><label for="validationDefault01">First name</label><input type="text" class="form-control" id="validationDefault01" placeholder="First name" value="Shaun" required></div><div class="col-md-4 mb-4"><label for="validationDefault02">Last name</label><input type="text" class="form-control" id="validationDefault02" placeholder="Last name" value="Park" required></div><div class="col-md-4 mb-4"><label for="validationDefaultUsername">Username</label><div class="input-group"><div class="input-group-prepend"><span class="input-group-text" id="inputGroupPrepend2">@</span></div><input type="text" class="form-control" id="validationDefaultUsername" placeholder="Username" aria-describedby="inputGroupPrepend2" required></div></div></div><div class="form-row"><div class="col-md-6 mb-4"><label for="validationDefault03">City</label><input type="text" class="form-control" id="validationDefault03" placeholder="City" required></div><div class="col-md-3 mb-4"><label for="validationDefault04">State</label><input type="text" class="form-control" id="validationDefault04" placeholder="State" required></div><div class="col-md-3 mb-4"><label for="validationDefault05">Zip</label><input type="text" class="form-control" id="validationDefault05" placeholder="Zip" required></div></div><div class="form-group mb-4"><div class="custom-control custom-checkbox checkbox-info"><input type="checkbox" class="custom-control-input" id="invalidCheck2" required><label class="custom-control-label" for="invalidCheck2">Agree to terms and conditions</label><div class="invalid-feedback">Agree to terms and conditions </div></div></div><button class="btn btn-primary mt-3" type="submit">Submit form</button></form>

=============== HTML =============== <form class="needs-validation" novalidate action="javascript:void(0);"><div class="form-row"><div class="col-md-4 mb-5"><label for="validationTooltip01">First name</label><input type="text" class="form-control" id="validationTooltip01" placeholder="First name" value="Shaun" required><div class="valid-tooltip">Looks good!</div></div><div class="col-md-4 mb-5"><label for="validationTooltip02">Last name</label><input type="text" class="form-control" id="validationTooltip02" placeholder="Last name" value="Park" required><div class="valid-tooltip">Looks good!</div></div><div class="col-md-4 mb-5"><label for="validationTooltipUsername">Username</label><div class="input-group"><div class="input-group-prepend"><span class="input-group-text" id="validationTooltipUsernamePrepend">@</span></div><input type="text" class="form-control" id="validationTooltipUsername" placeholder="Username" aria-describedby="validationTooltipUsernamePrepend" required><div class="invalid-tooltip">Please choose a unique and valid username. </div></div></div></div><div class="form-row"><div class="col-md-6 mb-5"><label for="validationTooltip03">City</label><input type="text" class="form-control" id="validationTooltip03" placeholder="City" required><div class="invalid-tooltip">Please provide a valid city. </div></div><div class="col-md-3 mb-5"><label for="validationTooltip04">State</label><input type="text" class="form-control" id="validationTooltip04" placeholder="State" required><div class="invalid-tooltip">Please provide a valid state. </div></div><div class="col-md-3 mb-5"><label for="validationTooltip05">Zip</label><input type="text" class="form-control" id="validationTooltip05" placeholder="Zip" required><div class="invalid-tooltip">Please provide a valid zip. </div></div></div><button class="btn btn-primary mt-2" type="submit">Submit form</button></form>

=============== Javascript =============== 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);