Answers for "target class [capitaincontroller] does not exist. laravel 8"

Target class [Controller] does not exist.

//accessing any function in the controller (this is web.php file)
use App\Http\Controllers\PostsController;

Route::get('/post', 'App\Http\Controllers\PostsController@index');

target class usercontroller does not exist. in laravel 8

use App\Http\Controllers\UserController;
//this is for admin controllers like this
use App\Http\Controllers\Admin\UserController;