Limit Comments & Display Character Count

if ( ! class_exists( 'WPCode_Comment_Limit_Counter' ) ) {

	class WPCode_Comment_Limit_Counter {

		// Update this value to change the maximum number of characters allowed in a comment.

		protected $comment_max_length = 1000;

		// Update this value to change the minimum number of characters that a comment must have to go through.

		protected $comment_min_length = 10;

		public function __construct() {

			add_action( 'comment_form', array( $this, 'add_comment_counter_markup' ) );

			add_action( 'comment_form', array( $this, 'add_comment_counter_js' ) );

			add_filter( 'preprocess_comment', array( $this, 'prevent_long_comments' ) );

		}

		public function add_comment_counter_markup() {

			?>

			<div id="comment-counter" style="margin-top: 10px;">Characters:

				<span id="comment-counter-count">0</span>/<?php echo absint( $this->comment_max_length ); ?>

			</div>

			<?php

		}

		public function add_comment_counter_js() {

			?>

			<script type="text/javascript">

				document.addEventListener( 'DOMContentLoaded', function () {

					var commentTextarea = document.getElementById( 'comment' );

					var counterDisplay = document.getElementById( 'comment-counter-count' );

					function updateCounter() {

						counterDisplay.textContent = commentTextarea.value.length;

					}

					commentTextarea.addEventListener( 'input', updateCounter );

					updateCounter();

				} );

			</script>

			<?php

		}

		public function prevent_long_comments( $comment ) {

			if ( strlen( $comment['comment_content'] ) > $this->comment_max_length ) {

				wp_die( sprintf( 'Comment is too long. Please keep your comment under %s characters.', $this->comment_max_length ) );

			}

			if ( strlen( $comment['comment_content'] ) < $this->comment_min_length ) {

				wp_die( sprintf( 'Comment is too short. Please use at least %s characters.', $this->comment_min_length ) );

			}

			return $comment;

		}

	}

}

new WPCode_Comment_Limit_Counter();