how can create helper function in laravel code example

Example: laravel add utility class

# How to register utilities class on Laravel 5.8
# File: composer.json
# ref: https://stackoverflow.com/questions/28290332/best-practices-for-custom-helpers-in-laravel-5
"autoload": {
    "classmap": [
        ...
    ],
    "psr-4": {
        "App\\": "app/"
    },
    "files": [
        "app/helpers.php" // <---- ADD THIS
    ]
},
 
 # Then run: `composer dump-autoload`