Unable to return values from function

Question

The function below is intended to return a list of the WordPress submenu pages.

function get_admin_menus() {
    global $submenu, $menu, $pagenow;
    if ( current_user_can('manage_options') ) {
        if( $pagenow == 'index.php' ) {
        foreach ( $submenu as $index => $menu_item ) {
            foreach ( $menu_item as $value) {
      
                    $submenu_page = $value[2];
                
                    // return $submenu_page;
                    echo $submenu_page;

                }
            }
        }
    }
}

Adding the action add_action( 'admin_notices', 'get_admin_menus' ); displays a list of the submenu items. This only works with echo.

I would like to return the values into another function however when using return $submenu_page with echo get_admin_menus() does not appear to work.

For example:

function test () {
  echo get_admin_menus();
}

What am I missing or doing wrong?

Answer 1

The foreach surrounding your return line means only the first item will be returned - perhaps that's what you want?

If not, then you should assign $value[2] to a local variable (concatenating if you want a string, or an array perhaps?) and the return the local variable after the loop.

function get_admin_menus() {
    global $submenu, $menu, $pagenow;
    $r = '';
    if ( current_user_can('manage_options') ) {
        if( $pagenow == 'index.php' ) {
        foreach ( $submenu as $index => $menu_item ) {
            foreach ( $menu_item as $value ) {
                    $r .= $value[2];
                }
            }
        }
    }
    return $r;
}