PHP - 在不同的函数中使用函数的返回值

Question

So I have two functions. Once returns some information and I am trying to get this to be accessible in my second function but this is currently empty/ Here is my first function code:

function get_current_user_role_custom() {
    global $wp_roles;

    $current_user = wp_get_current_user();
    $roles = $current_user->roles;
    $role = array_shift( $roles );

    return isset( $wp_roles->role_names[ $role ] ) ? translate_user_role( $wp_roles->role_names[ $role ] ) : FALSE;
}
$user_role = get_current_user_role_custom();

And the second function (which I am trying to use the $user_role variable in:

function new_customer_registered_send_email_admin() {

    //variables
    global $user_role;
    global $current_user;
    $current_user = wp_get_current_user();


    ob_start();
    do_action('woocommerce_email_header', 'New customer registered');
    $email_header = ob_get_clean();
    ob_start();
    do_action('woocommerce_email_footer');
    $email_footer = ob_get_clean();

    woocommerce_mail(
    get_bloginfo('admin_email'),
    get_bloginfo('name').' - New customer registered',
    $email_header.'<p>User Role: ' . $user_role . '</p>'.$email_footer
    );
}
add_action('new_customer_registered', 'new_customer_registered_send_email_admin');

Answer 1

Unless you have a really good reason why you must use global variables (which is almost never the case), do not use global variables. Instead use a parameter / an argument to hand over variables and thus their values to functions.

Try something like this:

// ### Define Functions ###
function get_current_user_role_custom($wp_roles) {
    $current_user = wp_get_current_user();
    $roles = $current_user->roles;
    $role = array_shift( $roles );

    return isset( $wp_roles->role_names[ $role ] ) ? translate_user_role( $wp_roles->role_names[ $role ] ) : FALSE;
}

function new_customer_registered_send_email_admin($user_role) {

    //variables
    $current_user = wp_get_current_user();

    ob_start();
    do_action('woocommerce_email_header', 'New customer registered');
    $email_header = ob_get_clean();
    ob_start();
    do_action('woocommerce_email_footer');
    $email_footer = ob_get_clean();

    woocommerce_mail(
    get_bloginfo('admin_email'),
    get_bloginfo('name').' - New customer registered',
    $email_header.'<p>User Role: ' . $user_role . '</p>'.$email_footer
    );
}

// ### Call Functions ###
// as I cannot see where this variable comes from, you need to modify the follwoing line yourself appropriately ;)
$wp_roles = get_wp_roles_somehow();
$user_role = get_current_user_role_custom($wp_roles);
if ($user_role !== FALSE) {
    new_customer_registered_send_email_admin($user_role);
    add_action('new_customer_registered', 'new_customer_registered_send_email_admin');    
} else {
    // handle error somehow
}