Task-11: Alter an existing simple form

example.module

<?php

/**
 * @file
 * Change the label of Comment form button to 'Add Comment' 
 */
 
use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_form_alter().
 */
function example_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  if ($form_id == 'comment_comment_form') {
    $form['actions']['submit']['#value'] = t('Add Comment');
  }
}