I have upgraded Laravel from 5.6 to 6.0. Previously, default helper functions were running fine on the controllers, but now it says \"undefined.\" In my con
Likelihood Of Impact: High Laravel 6 Upgrade Guide
In Laravel 6 All str_ and array_ helpers have been moved to the new laravel/helpers Composer package and removed from the framework. If desired, you may update all calls to these helpers to use the Illuminate\Support\Str and Illuminate\Support\Arr classes. Alternatively, you can add the new laravel/helpers package to your application to continue using these helpers:
composer require laravel/helpers
If don't want to add Package then Used Str And Arr Classes.
For Example :
Str::random(12)
https://laravel.com/docs/master/helpers#method-str-random