rules multiple uploads

Validation of arrays with "ordinary data fields": https://codeigniter4.github.io/userguide...are-arrays

Yes, thanks, I read it. Here, just show me how to check for int data such data from the form:

Code:

<input name="id_cat[]" />
<input name="id_cat[]" />
<input name="id_cat[]" />
...

PHP Code:

$this->validate([
    'id_cat' => ['label' => 'Error message', 'rules' => 'required|numeric']
    // ...
]); 


PHP Code:

/**
     * Numeric
     *
     * @param string $str
     *
     * @return boolean
     */
    public function numeric(string $str = null): bool
    {
        return (bool) preg_match('/^[\-+]?[0-9]*\.?[0-9]+$/', $str);
    } 


There will be an error, because the method waits for the string, and the array arrives ...
Error:
Argument 1 passed to CodeIgniter\\Validation\\FormatRules::numeric() must be of the type string or null, array given, called in D:\\OpenServer\\OSPanel\\domains\\ci4.ru\\system\\Validation\\Validation.php on line 279