bootstrap constrained text box code example

Example 1: bootstrap input field validation

<form>
  <div class="form-row">
    <div class="col-md-4 mb-3">
      <label for="validationServer01">First name</label>
      <input type="text" class="form-control is-valid" id="validationServer01" placeholder="First name" value="Mark" required>
      <div class="valid-feedback">
        Looks good!
      </div>
    </div>
    <div class="col-md-4 mb-3">
      <label for="validationServer02">Last name</label>
      <input type="text" class="form-control is-valid" id="validationServer02" placeholder="Last name" value="Otto" required>
      <div class="valid-feedback">
        Looks good!
      </div>
    </div>
    <div class="col-md-4 mb-3">
      <label for="validationServerUsername">Username</label>
      <div class="input-group">
        <div class="input-group-prepend">
          <span class="input-group-text" id="inputGroupPrepend3">@</span>
        </div>
        <input type="text" class="form-control is-invalid" id="validationServerUsername" placeholder="Username" aria-describedby="inputGroupPrepend3" required>
        <div class="invalid-feedback">
          Please choose a username.
        </div>
      </div>
    </div>
  </div>
  <div class="form-row">
    <div class="col-md-6 mb-3">
      <label for="validationServer03">City</label>
      <input type="text" class="form-control is-invalid" id="validationServer03" placeholder="City" required>
      <div class="invalid-feedback">
        Please provide a valid city.
      </div>
    </div>
    <div class="col-md-3 mb-3">
      <label for="validationServer04">State</label>
      <input type="text" class="form-control is-invalid" id="validationServer04" placeholder="State" required>
      <div class="invalid-feedback">
        Please provide a valid state.
      </div>
    </div>
    <div class="col-md-3 mb-3">
      <label for="validationServer05">Zip</label>
      <input type="text" class="form-control is-invalid" id="validationServer05" placeholder="Zip" 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 is-invalid" type="checkbox" value="" id="invalidCheck3" required>
      <label class="form-check-label" for="invalidCheck3">
        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>

Example 2: bootstrap forms

Example of .form-group
<form>
 <div class=”form-group”>
 <label for=”exampleInputEmail1”>Email 

address</label>
 <input type=”email” class=”form-control” id=”exampleInputEmail1” ariadescribedby=”emailHelp” placeholder=”Provide email”>
 </div>
 <div class=”form-group”>
 <label for=”exampleInputPassword1”>Your password</label>
 <input type=”password” class=”form-control” id=”exampleInputPassword1”
placeholder=”Password”>
 </div>
 <div class=”form-group form-check”>
 <input type=”checkbox” class=”form-check-input” id=”exampleCheck1”>
 <label class=”form-check-label” for=”exampleCheck1”>Remember me</label>
 </div>
 <button type=”submit” class=”btn btn-primary”>Submit</button>
</form>
.form-control
Use this class to style all textual form controls such as user input, titles, etc.
<form>
 <div class=”form-group”>
 <label for=”exampleFormControlInput1”>Email address</label>
 <input type=”email” class=”form-control” id=”exampleFormControlInput1”
placeholder=”name@example.com”>
 </div>
.form-control-file
Add this class whenever you need to provide the user with an option to upload a file to the form.
<input type=”file” class=”form-control-file” id=”exampleFormControlFile1”>
.form-control-lg and .form-control-sm.
Create a visual hierarchy within your form by adding .form-control-lg to make bigger input areas and .form-control-sm to
make smaller ones.
<input class=”form-control form-control-lg” type=”text” placeholder=”.form-controllg”>
<input class=”form-control form-control-sm” type=”text” placeholder=”.form-controlsm”>