wp-includes/class-wp-customize-widgets.php:626Converts a widget ID into its id_base and number components.
$widget_idstringarray public function parse_widget_id( $widget_id ) { $parsed = array( 'number' => null, 'id_base' => null, ); if ( preg_match( '/^(.+)-(\d+)$/', $widget_id, $matches ) ) { $parsed['id_base'] = $matches[1]; $parsed['number'] = (int) $matches[2]; } else { // Likely an old single widget. $parsed['id_base'] = $widget_id; } return $parsed; }Introduced in 3.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-customize-widgets.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.