how to create helper file in laravel code example

Example 1: laravel helper functions

$callback = function ($value) {
    return (is_numeric($value)) ? $value * 2 : 0;
};

$result = with(5, $callback);

// 10

$result = with(null, $callback);

// 0

$result = with(5, null);

// 5

Example 2: laravel helper

use Illuminate\Support\Str;

$length = Str::length('Laravel');

// 7