print_footer_scripts(): string[]

Compatibility

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

Return value

string[]

Handles of the scripts that were printed.

Performance profile

How much work a call to print_footer_scripts() 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

Moderate

Reads stored settings via get_site_option(), cached per request but not free on a cold cache.

Scaling

Constant

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

Instructions

5–21

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 22.

Plugin surface

1 hook

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

Called by

4

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

What it touches

• hookthird-party callbacksapply_filters()called directly
• optionnetwork optionget_site_option()one call below print_footer_scripts()

Further down the call graph this can also reach cache, serialize, query 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 · 3 distinct outcomes

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

Hooks and filters fired · 1

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

1. 1
   apply_filters( print_footer_scripts )filterline 2203 (+17 into the body)

   Filters whether to print the footer scripts.

Uses · 3

• script_concat_settings()Determines the concatenation and compression settings for scripts and styles.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• _print_scripts()Prints scripts (internal use only)

Used by · 4

• _wp_footer_scripts()Private, for use in *_footer_scripts hooks
• wp_font_library_render_page()Render the font-library page.
• wp_hoist_late_printed_styles()Adds the hooks needed for CSS output to be delayed until after the content of the page has been established.
• wp_options_connectors_render_page()Render the options-connectors page.

Source code

View on Trac ↗View on GitHub ↗

2186function print_footer_scripts() {2187	global $wp_scripts, $concatenate_scripts;2188 2189	if ( ! ( $wp_scripts instanceof WP_Scripts ) ) {2190		return array(); // No need to run if not instantiated.2191	}2192	script_concat_settings();2193	$wp_scripts->do_concat = $concatenate_scripts;2194	$wp_scripts->do_footer_items();2195 2196	/**2197	 * Filters whether to print the footer scripts.2198	 *2199	 * @since 2.8.02200	 *2201	 * @param bool $print Whether to print the footer scripts. Default true.2202	 */2203	if ( apply_filters( 'print_footer_scripts', true ) ) {2204		_print_scripts();2205	}2206 2207	$wp_scripts->reset();2208	return $wp_scripts->done;2209}

Changelog

Introduced in 2.8.0. One change between 6.7.7 and 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 7.0.4 tag, from src/wp-includes/script-loader.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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