Answers for "class not found laravel 8 while it exists"

laravel target class does not exist

Uncomment this line in app>>provider>>RouteServiceProvider.php file
// protected $namespace = 'App\\Http\\Controllers';

causes of class not found in laravel

the possible cause of this error can be:
1 class doesn’t exist
2.the class name case is not the same for example - Jalalian.php and jalalian.php are not the same even when the class name case is the same check to confirm that use statement has the right letter case. 
3. wrong namespace