<form>
   <div class="form-row">
      <div class="col-md-6 mb-3">
         <label for="validationDefault01">First name</label>
         <input type="text" class="form-control" id="validationDefault01" required>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationDefault02">Last name</label>
         <input type="text" class="form-control" id="validationDefault02" required>
      </div>
      <div class="col-md-6 mb-3">
         <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"  aria-describedby="inputGroupPrepend2" required>
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationDefault03">City</label>
         <input type="text" class="form-control" id="validationDefault03" required>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationDefault04">State</label>
         <select class="form-control" id="validationDefault04" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
         </select>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationDefault05">Zip</label>
         <input type="text" class="form-control" id="validationDefault05" required>
      </div>
   </div>
   <div class="form-group">
      <div class="form-check">
         <input class="form-check-input" type="checkbox" value="" id="invalidCheck2" required>
         <label class="form-check-label" for="invalidCheck2">
         Agree to terms and conditions
         </label>
      </div>
   </div>
   <div class="form-group">
      <button class="btn btn-primary" type="submit">Submit form</button>
   </div>
</form>

<form class="was-validated">
   <div class="mb-3">
      <label for="validationTextarea">Textarea</label>
      <textarea class="form-control is-invalid" id="validationTextarea" placeholder="Required example textarea" required></textarea>
      <div class="invalid-feedback">
         Please enter a message in the textarea.
      </div>
   </div>
   <div class="custom-control custom-checkbox mb-3">
      <input type="checkbox" class="custom-control-input" id="customControlValidation1" required>
      <label class="custom-control-label" for="customControlValidation1">Check this custom checkbox</label>
      <div class="invalid-feedback">Example invalid feedback text</div>
   </div>
   <div class="custom-control custom-radio">
      <input type="radio" class="custom-control-input" id="customControlValidation2" name="radio-stacked" required>
      <label class="custom-control-label" for="customControlValidation2">Toggle this custom radio</label>
   </div>
   <div class="custom-control custom-radio mb-3">
      <input type="radio" class="custom-control-input" id="customControlValidation3" name="radio-stacked" required>
      <label class="custom-control-label" for="customControlValidation3">Or toggle this other custom radio</label>
      <div class="invalid-feedback">More example invalid feedback text</div>
   </div>
   <div class="form-group">
      <select class="custom-select" required>
         <option value="">Open this select menu</option>
         <option value="1">One</option>
         <option value="2">Two</option>
         <option value="3">Three</option>
      </select>
      <div class="invalid-feedback">Example invalid custom select feedback</div>
   </div>
   <div class="custom-file">
      <input type="file" class="custom-file-input" id="validatedCustomFile" required>
      <label class="custom-file-label" for="validatedCustomFile">Choose file...</label>
      <div class="invalid-feedback">Example invalid custom file feedback</div>
   </div>
</form>

<form class="needs-validation" novalidate>
   <div class="form-row">
      <div class="col-md-6 mb-3">
         <label for="validationCustom01">First name</label>
         <input type="text" class="form-control" id="validationCustom01"  required>
         <div class="valid-feedback">
            Looks good!
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationCustom02">Last name</label>
         <input type="text" class="form-control" id="validationCustom02"  required>
         <div class="valid-feedback">
            Looks good!
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <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" aria-describedby="inputGroupPrepend" required>
            <div class="invalid-feedback">
               Please choose a username.
            </div>
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationCustom03">City</label>
         <input type="text" class="form-control" id="validationCustom03" required>
         <div class="invalid-feedback">
            Please provide a valid city.
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationCustom04">State</label>
         <select class="form-control" id="validationCustom04" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
         </select>
         <div class="invalid-feedback">
            Please select a valid state.
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationCustom05">Zip</label>
         <input type="text" class="form-control" id="validationCustom05" required>
         <div class="invalid-feedback">
            Please provide a valid zip.
         </div>
      </div>
   </div>
   <div class="form-group">
      <div class="form-check">
         <input class="form-check-input" type="checkbox" value="" id="invalidCheck" required>
         <label class="form-check-label" for="invalidCheck">
         Agree to terms and conditions
         </label>
         <div class="invalid-feedback">
            You must agree before submitting.
         </div>
      </div>
   </div>
   <button class="btn btn-primary" type="submit">Submit form</button>
</form>

<form class="needs-validation" novalidate>
   <div class="form-row">
      <div class="col-md-6 mb-3">
         <label for="validationTooltip01">First name</label>
         <input type="text" class="form-control" id="validationTooltip01" value="Mark" required>
         <div class="valid-tooltip">
            Looks good!
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationTooltip02">Last name</label>
         <input type="text" class="form-control" id="validationTooltip02" value="Tech" required>
         <div class="valid-tooltip">
            Looks good!
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <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" aria-describedby="validationTooltipUsernamePrepend" required>
            <div class="invalid-tooltip">
               Please choose a unique and valid username.
            </div>
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationTooltip03">City</label>
         <input type="text" class="form-control" id="validationTooltip03" required>
         <div class="invalid-tooltip">
            Please provide a valid city.
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationTooltip04">State</label>
         <select class="form-control" id="validationTooltip04" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
         </select>
         <div class="invalid-tooltip">
            Please select a valid state.
         </div>
      </div>
      <div class="col-md-6 mb-3">
         <label for="validationTooltip05">Zip</label>
         <input type="text" class="form-control" id="validationTooltip05" required>
         <div class="invalid-tooltip">
            Please provide a valid zip.
         </div>
      </div>
   </div>
   <button class="btn btn-primary" type="submit">Submit form</button>
</form>