我正在尝试理解我在网上找到的创建自定义用户登录页面的代码。这里我无法理解foreach循环是如何工作的（特别是这一行：$page\\u definitions as$slug=>$page in foreach参数）。我对使用数组非常陌生，正在努力学习它是如何工作的。

class Personalize_Login_Plugin {

    public static function plugin_activated() {
        // Information needed for creating the plugin\'s pages
        $page_definitions = array(
            \'member-login\' => array(
                \'title\' => __( \'Sign In\', \'personalize-login\' ),
                \'content\' => \'[custom-login-form]\'
            ),
            \'member-account\' => array(
                \'title\' => __( \'Your Account\', \'personalize-login\' ),
                \'content\' => \'[account-info]\'
            ),
        );

        foreach ( $page_definitions as $slug => $page ) {
            // Check that the page doesn\'t exist already
            $query = new WP_Query( \'pagename=\' . $slug );
            if ( ! $query->have_posts() ) {
                // Add the page using the data from the array above
                wp_insert_post(
                    array(
                        \'post_content\'   => $page[\'content\'],
                        \'post_name\'      => $slug,
                        \'post_title\'     => $page[\'title\'],
                        \'post_status\'    => \'publish\',
                        \'post_type\'      => \'page\',
                        \'ping_status\'    => \'closed\',
                        \'comment_status\' => \'closed\',
                    )
                );
            }
        }
    }
    public function __construct() {

    }
}