How can reserved words and duplicate names in form elements impact PHP scripts?

Reserved words and duplicate names in form elements can impact PHP scripts by causing conflicts and errors in the code. To solve this issue, it is important to avoid using reserved words as form element names and ensure that each form element has a unique name.

<form method="post" action="process_form.php">
  <input type="text" name="username" placeholder="Username">
  <input type="password" name="password" placeholder="Password">
  <input type="submit" value="Submit">
</form>