function your_function( $parameters ) {
//function logic
}
function your_another_function( $parameters ) {
//function logic
}
// composer.json
"autoload": {
...
"files": [
"app/Helpers/your_helper_function.php"
]
...
}
// Now call from any class of Laravel
class UserController extends Controller {
public function storeUser() {
your_function();
// do other stuffs
}
}