What are the advantages and disadvantages of using a dropdown menu for selecting country codes versus allowing freeform input for phone numbers in a PHP form?

When designing a form for phone number input in PHP, using a dropdown menu for selecting country codes can provide a more user-friendly experience by reducing errors and ensuring standardized formatting. However, it may limit flexibility for users with international numbers or those from countries not listed in the dropdown menu. Allowing freeform input for phone numbers gives users more freedom but may result in inconsistencies in formatting and potential errors.

<!-- Example code for dropdown menu for country codes -->
<select name="country_code">
  <option value="+1">USA (+1)</option>
  <option value="+44">UK (+44)</option>
  <option value="+61">Australia (+61)</option>
  <!-- Add more country codes as needed -->
</select>
<input type="text" name="phone_number" placeholder="Phone Number">

<!-- Example code for freeform input for phone numbers -->
<input type="text" name="phone_number" placeholder="Phone Number">