wp_nav_menu_remove_menu_item_has_children_class( string[] $classes, WP_Post $menu_item, stdClass|false $args = false, int|false $depth = false ): string[]

664function wp_nav_menu_remove_menu_item_has_children_class( $classes, $menu_item, $args = false, $depth = false ) {665	/*666	 * Account for the filter being called without the $args or $depth parameters.667	 *668	 * This occurs when a theme uses a custom walker calling the `nav_menu_css_class`669	 * filter using the legacy formats prior to the introduction of the $args and670	 * $depth parameters.671	 *672	 * As both of these parameters are required for this function to determine673	 * both the current and maximum depth of the menu tree, the function does not674	 * attempt to remove the `menu-item-has-children` class if these parameters675	 * are not set.676	 */677	if ( false === $depth || false === $args ) {678		return $classes;679	}680 681	// Max-depth is 1-based.682	$max_depth = isset( $args->depth ) ? (int) $args->depth : 0;683	// Depth is 0-based so needs to be increased by one.684	$depth = $depth + 1;685 686	// Complete menu tree is displayed.687	if ( 0 === $max_depth ) {688		return $classes;689	}690 691	/*692	 * Remove the `menu-item-has-children` class from bottom level menu items.693	 * -1 is used to display all menu items in one level so the class should694	 * be removed from all menu items.695	 */696	if ( -1 === $max_depth || $depth >= $max_depth ) {697		$classes = array_diff( $classes, array( 'menu-item-has-children' ) );698	}699 700	return $classes;701}
When	Instructions	Calls it makes
always	7–23	none
`$depth !== false && $args !== false && $max_depth !== 0`	24–28	`array_diff()`