How to pass a variable from one controller to another laravel

I'm trying to pass a variable from a controller to some another controller. I'm doing it like this-

SomeController

public function index(){
  $var = 'variable';
  return redirect()->route('toAnotherController')->with('var', $var);
}

Route.php

Route::get('/anotherController', 'AnotherController@index')->name('toAnotherController');

Another Controller

public function index(){
  echo $var;
}

But, this is giving an error "Undefined variable $var". What is going wrong here? Is there any other way to do this?

via Chebli Mohamed