wp_page_menu( array|string $args = array() )

function wp_page_menu( $args = array() ) {
	$defaults = array(
		'sort_column'  => 'menu_order, post_title',
		'menu_id'      => '',
		'menu_class'   => 'menu',
		'container'    => 'div',
		'echo'         => true,
		'link_before'  => '',
		'link_after'   => '',
		'before'       => '<ul>',
		'after'        => '</ul>',
		'item_spacing' => 'discard',
		'walker'       => '',
	);
	$args = wp_parse_args( $args, $defaults );

	if ( ! in_array( $args['item_spacing'], array( 'preserve', 'discard' ) ) ) {
		// invalid value, fall back to default.
		$args['item_spacing'] = $defaults['item_spacing'];
	}

	if ( 'preserve' === $args['item_spacing'] ) {
		$t = "\t";
		$n = "\n";
	} else {
		$t = '';
		$n = '';
	}

	/**
	 * Filters the arguments used to generate a page-based menu.
	 *
	 * @since WP-2.7.0
	 *
	 * @see wp_page_menu()
	 *
	 * @param array $args An array of page menu arguments.
	 */
	$args = apply_filters( 'wp_page_menu_args', $args );

	$menu = '';

	$list_args = $args;

	// Show Home in the menu
	if ( ! empty($args['show_home']) ) {
		if ( true === $args['show_home'] || '1' === $args['show_home'] || 1 === $args['show_home'] )
			$text = __('Home');
		else
			$text = $args['show_home'];
		$class = '';
		if ( is_front_page() && !is_paged() )
			$class = 'class="current_page_item"';
		$menu .= '<li ' . $class . '><a href="' . home_url( '/' ) . '">' . $args['link_before'] . $text . $args['link_after'] . '</a></li>';
		// If the front page is a page, add it to the exclude list
		if (get_option('show_on_front') == 'page') {
			if ( !empty( $list_args['exclude'] ) ) {
				$list_args['exclude'] .= ',';
			} else {
				$list_args['exclude'] = '';
			}
			$list_args['exclude'] .= get_option('page_on_front');
		}
	}

	$list_args['echo'] = false;
	$list_args['title_li'] = '';
	$menu .= wp_list_pages( $list_args );

	$container = sanitize_text_field( $args['container'] );

	// Fallback in case `wp_nav_menu()` was called without a container.
	if ( empty( $container ) ) {
		$container = 'div';
	}

	if ( $menu ) {

		// wp_nav_menu doesn't set before and after
		if ( isset( $args['fallback_cb'] ) &&
			'wp_page_menu' === $args['fallback_cb'] &&
			'ul' !== $container ) {
			$args['before'] = "<ul>{$n}";
			$args['after'] = '</ul>';
		}

		$menu = $args['before'] . $menu . $args['after'];
	}

	$attrs = '';
	if ( ! empty( $args['menu_id'] ) ) {
		$attrs .= ' id="' . esc_attr( $args['menu_id'] ) . '"';
	}

	if ( ! empty( $args['menu_class'] ) ) {
		$attrs .= ' class="' . esc_attr( $args['menu_class'] ) . '"';
	}

	$menu = "<{$container}{$attrs}>" . $menu . "</{$container}>{$n}";

	/**
	 * Filters the HTML output of a page-based menu.
	 *
	 * @since WP-2.7.0
	 *
	 * @see wp_page_menu()
	 *
	 * @param string $menu The HTML output.
	 * @param array  $args An array of arguments.
	 */
	$menu = apply_filters( 'wp_page_menu', $menu, $args );
	if ( $args['echo'] )
		echo $menu;
	else
		return $menu;
}