Use blank() and filled() Instead of empty() in Laravel

PHP's empty() treats 0, '0', and false as empty. Laravel's blank() and filled() helpers handle these values intuitively without silent bugs.

PHP's empty() is notoriously loose: it considers 0 and '0' empty. Laravel provides blank() and filled() as safer alternatives.

if (blank($request->input('quantity'))) {
    return 'Quantity is required';
}

• blank() treats 0 and '0' as filled values, not blank
• filled() is the exact inverse of blank()
• Handles whitespace-only strings correctly