JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <div>
        First name: <input type="text" name="firstname" id="firstname"><br>
    </div>
    <div>
        Last name: <input type="text" name="lastname" id="lastname"><br>
    </div>
    <div>
        Full name: <input type="text" name="fullname" id="fullname"><br>
    </div>
</form>

JavaScript

$(document).ready(function(){
    if($('#firstname').is(':visible') || $('#lastname').is(':visible'))
        $('#fullname').parent().hide();
        
})