comment_class │ filter-hook │ WP 2.7.0

Allows you to change the list of CSS classes applied to each comment <li> tag in the template.

Applies when the HTML wrapper for a comment is generated in the template. This allows classes assigned to the comment element to be added, changed, or removed.

It can be used in a theme file (for example, comments.php) where comment_class() is called.

Usage

add_filter( 'comment_class', 'wp_kama_comment_class_filter', 10, 5 );

/**
 * Function for `comment_class` filter-hook.
 * 
 * @param string[]    $classes    An array of comment classes.
 * @param string[]    $css_class  An array of additional classes added to the list.
 * @param string      $comment_id The comment ID as a numeric string.
 * @param WP_Comment  $comment    The comment object.
 * @param int|WP_Post $post       The post ID or WP_Post object.
 *
 * @return string[]
 */
function wp_kama_comment_class_filter( $classes, $css_class, $comment_id, $comment, $post ){

	// filter...
	return $classes;
}

$classes(array)

An array of CSS classes applied to the comment tag.

$css_class(array)

An array of additional CSS classes applied to the comment tag — the first parameter of get_comment_class().

$comment_id(string)

The comment ID. An integer represented as a string.

$comment(WP_Comment)

The current comment object.

$post(int|WP_Post)

The post object to which the comment belongs.

Examples

#1 Add a custom class to comments

Add the my-comment CSS class to all comments.

add_filter( 'comment_class', function( $classes ) {
	$classes[] = 'my-comment';

	return $classes;
} );

#2 Add a class to comments by the post author

Add the by-post-author class if the comment author is also the post author.

add_filter( 'comment_class', function( $classes, $_, $__, $comment, $post ) {
	if ( $comment->user_id === $post->post_author ) {
		$classes[] = 'by-post-author';
	}

	return $classes;
}, 10, 5 );