Detect Empty Values in Laravel with the blank Function

Validating empty values in PHP can be tricky. Laravel's blank function simplifies this process by providing a consistent way to check for 'blank' values.

Basic Usage

The blank function works with various types:

// Returns true
blank('');
blank(' ');
blank(null);
blank(collect());

// Returns false
blank(0);
blank(true);
blank(false);

Real-World Example

Here's how you might use it in a form validation context:

class SubmissionValidator
{
    public function validateUserInput(array $input)
    {
        $errors = [];

        // Check required fields
        foreach (['name', 'email', 'message'] as $field) {
            if (blank($input[$field] ?? null)) {
                $errors[$field] = "The {$field} field is required";
            }
        }

        // Check optional fields with special conditions
        if (!blank($input['phone'] ?? null) && !preg_match('/^[0-9-+\s()]*$/', $input['phone'])) {
            $errors['phone'] = 'Invalid phone format';
        }

        // Validate array inputs
        if (!blank($input['interests'] ?? null)) {
            if (count($input['interests']) < 2) {
                $errors['interests'] = 'Please select at least 2 interests';
            }
        }

        return [
            'valid' => empty($errors),
            'errors' => $errors
        ];
    }

    public function processOrder($orderData)
    {
        // Skip empty notes
        if (!blank($orderData['notes'])) {
            $this->addOrderNotes($orderData['notes']);
        }

        // Check for empty shipping details
        if (blank($orderData['shipping_address'])) {
            throw new InvalidOrderException('Shipping address is required');
        }
    }
}

The blank function provides a reliable way to check for empty values, making your validation logic cleaner and more consistent.

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