PHP 8.4 Property Hooks
PHP 8.4 introduces property hooks, a powerful feature that allows you to add custom logic when getting or setting properties.
Basic Example
class User
{
public string $name {
get => strtoupper($this->name);
set => ucfirst($value);
}
}
$user = new User();
$user->name = 'john doe';
echo $user->name; // Output: JOHN DOE
Computed Properties
Create virtual properties without backing storage:
class Rectangle
{
public function __construct(
public float $width,
public float $height
) {}
public float $area {
get => $this->width * $this->height;
}
}
Validation in Setters
class Product
{
private float $_price;
public float $price {
get => $this->_price;
set {
if ($value < 0) {
throw new InvalidArgumentException('Price must be positive');
}
$this->_price = $value;
}
}
}
Benefits
- ✅ Cleaner than
__get()and__set()magic methods - ✅ Better IDE support and static analysis
- ✅ More explicit and readable code
- ✅ Type-safe property access
Property hooks make PHP objects more powerful while maintaining backward compatibility!
Thử thách tương tác
Thử thách
Luyện tập ngay điều vừa học. Viết lời giải, mở gợi ý nếu bí.
Đề bài
Add a computed `fahrenheit` property to the Temperature class using a PHP 8.4 property hook, so that reading $t->fahrenheit returns the Celsius value converted to Fahrenheit (F = C × 9/5 + 32) — no method call and no stored field.
Ngôn ngữPHP
Code khởi tạo
class Temperature
{
public function __construct(public float $celsius) {}
// TODO: add a virtual `fahrenheit` property using a get hook
}
$t = new Temperature(25);
echo $t->fahrenheit; // expected: 77Lời giải của bạn
class Temperature
{
public function __construct(public float $celsius) {}
public float $fahrenheit {
get => $this->celsius * 9 / 5 + 32;
}
}
$t = new Temperature(25);
echo $t->fahrenheit; // 77