unexpected route problem

if I use

Code:

$routes->post('login', 'Admin::do_login');

everything works as expected

but when I use

Code:

$routes->match(['get', 'post'], 'login', [Admin::class, 'do_login']);

I get an error

404 Controller or its method is not found: \Config\Admin::do_login

am I doing anything wrong?

The class name is Admin and the method name is do_login
The controller file name is Admin.php

Specify a class name with a namespace.

Specify a class name with a namespace.

can you explain how and why? i am new to this

because on the other hand, this works fine

Code:

$routes->match(['get', 'post'], 'appointment', [Appointment::class, 'appointmentForm']);

What are you new to? In php?

In the first example, the handler is specified as a string. In this case, the class will be checked for the existence of a namespace, and if it is not found, the default namespace will be added.

In the second example, you specify the handler as a string, where you declare the class name directly. If you don't specify a namespace or don't import, the current namespace will be used.
Current namespace is Config.

PHP Code:

namespace Config;

use Namespace\Example2; 

$routes->get('example1', [Example1::class, 'index']); // \Config\Example1
$routes->get('example2', [Example2::class, 'index']); // \Namespace\Example2
$routes->get('example3', ['\Namespace\Example3', 'index']); // \Namespace\Example3

$routes->get('example4', '\Namespace\Example4::index'); //  \Namespace\Example4
$routes->get('example5', 'Namespace\Example5::index'); //  \App\Controllers\Namespace\Example5 


Read https://www.php.net/manual/en/language.n...ionale.php
Namespaces was introduced in PHP 5.3.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

What are you new to? In php?

In the first example, the handler is specified as a string. In this case, the class will be checked for the existence of a namespace, and if it is not found, the default namespace will be added.

In the second example, you specify the handler as a string, where you declare the class name directly. If you don't specify a namespace or don't import, the current namespace will be used.
Current namespace is Config.

PHP Code:

namespace Config;

use Namespace\Example2; 

$routes->get('example1', [Example1::class, 'index']); // \Config\Example1
$routes->get('example2', [Example2::class, 'index']); // \Namespace\Example2
$routes->get('example3', ['\Namespace\Example3', 'index']); // \Namespace\Example3

$routes->get('example4', '\Namespace\Example4::index'); //  \Namespace\Example4
$routes->get('example5', 'Namespace\Example5::index'); //  \App\Controllers\Namespace\Example5 


Thank you for explaining in such a manner.
the problem is solved