get_body_class( string|string[] $css_class = '' ): string[]

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$css_classstring|string[]optional

Space-separated string or array of class names to add to the class list. Default empty.Default: ''

Return value

string[]

Array of class names.

Performance profile

How much work a call to get_body_class() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via get_pages().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

93–154

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 521.

Plugin surface

1 hook

Third-party callbacks on 'body_class' run inside this call, and their cost is not bounded by anything here.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• querycontent queryget_pages()called directly
• hookthird-party callbacksapply_filters()called directly
• regexregular expression over the whole inputpreg_split()called directly
• optionoption read or writeget_option()one call below get_body_class()

Further down the call graph this can also reach cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 120 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost get_body_class() can have, taken from its control-flow graph on PHP 8.5.

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Hooks and filters fired · 1

One hook fires while get_body_class() runs, in this order:

1. 1
   apply_filters( body_class )filterline 866 (+230 into the body)

   Filters the list of CSS body class names for the current post or page.

Uses · 38

• is_rtl()Determines whether the current locale is right-to-left (RTL).
• is_front_page()Determines whether the query is for the front page of the site.
• is_home()Determines whether the query is for the blog homepage.
• is_privacy_policy()Determines whether the query is for the Privacy Policy page.
• is_archive()Determines whether the query is for an existing archive page.
• is_date()Determines whether the query is for an existing date archive.
• is_search()Determines whether the query is for a search.
• is_paged()Determines whether the query is for a paged result and not for the first page.
• is_attachment()Determines whether the query is for an existing attachment page.
• is_404()Determines whether the query has resulted in a 404 (returns no results).
• is_singular()Determines whether the query is for an existing single post of any post type (post, attachment, page, custom post types).
• is_page_template()Determines whether the current post uses a page template.

Used by · 1

• body_class()Displays the class names for the body element.

Source code

View on Trac ↗View on GitHub ↗

636function get_body_class( $css_class = '' ) {637	global $wp_query;638 639	$classes = array();640 641	if ( is_rtl() ) {642		$classes[] = 'rtl';643	}644 645	if ( is_front_page() ) {646		$classes[] = 'home';647	}648	if ( is_home() ) {649		$classes[] = 'blog';650	}651	if ( is_privacy_policy() ) {652		$classes[] = 'privacy-policy';653	}654	if ( is_archive() ) {655		$classes[] = 'archive';656	}657	if ( is_date() ) {658		$classes[] = 'date';659	}660	if ( is_search() ) {661		$classes[] = 'search';662		$classes[] = $wp_query->posts ? 'search-results' : 'search-no-results';663	}664	if ( is_paged() ) {665		$classes[] = 'paged';666	}667	if ( is_attachment() ) {668		$classes[] = 'attachment';669	}670	if ( is_404() ) {671		$classes[] = 'error404';672	}673 674	if ( is_singular() ) {675		$post      = $wp_query->get_queried_object();676		$post_id   = $post->ID;677		$post_type = $post->post_type;678 679		$classes[] = 'wp-singular';680 681		if ( is_page_template() ) {682			$classes[] = "{$post_type}-template";683 684			$template_slug  = get_page_template_slug( $post_id );685			$template_parts = explode( '/', $template_slug );686 687			foreach ( $template_parts as $part ) {688				$classes[] = "{$post_type}-template-" . sanitize_html_class( str_replace( array( '.', '/' ), '-', basename( $part, '.php' ) ) );689			}690			$classes[] = "{$post_type}-template-" . sanitize_html_class( str_replace( '.', '-', $template_slug ) );691		} else {692			$classes[] = "{$post_type}-template-default";693		}694 695		if ( is_single() ) {696			$classes[] = 'single';697			if ( isset( $post->post_type ) ) {698				$classes[] = 'single-' . sanitize_html_class( $post->post_type, $post_id );699				$classes[] = 'postid-' . $post_id;700 701				// Post Format.702				if ( post_type_supports( $post->post_type, 'post-formats' ) ) {703					$post_format = get_post_format( $post->ID );704 705					if ( $post_format && ! is_wp_error( $post_format ) ) {706						$classes[] = 'single-format-' . sanitize_html_class( $post_format );707					} else {708						$classes[] = 'single-format-standard';709					}710				}711			}712		}713 714		if ( is_attachment() ) {715			$mime_type   = get_post_mime_type( $post_id );

Changelog

Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.9.7 tag, from src/wp-includes/post-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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