PHP 7 고급 기능: 익명 클래스를 사용하여 임시 개체를 만드는 방법

$calculator = new class {
    public function add($a, $b) {
        return $a + $b;
    }
    
    public function subtract($a, $b) {
        return $a - $b;
    }
    
    public function multiply($a, $b) {
        return $a * $b;
    }
    
    public function divide($a, $b) {
        return $a / $b;
    }
};

echo $calculator->add(2, 3); // 输出 5
echo $calculator->multiply(4, 5); // 输出 20

abstract class Shape {
    abstract public function area();
}

$circle = new class extends Shape {
    private $radius;
    
    public function __construct($radius) {
        $this->radius = $radius;
    }
    
    public function area() {
        return 3.14 * $this->radius * $this->radius;
    }
};

echo $circle->area(); // 输出 28.26

function createCalculator() {
    return new class {
        // ...
    };
}

$calculator = createCalculator(); // 错误，无法创建匿名类的实例

function createCalculator() {
    $calculator = new class {
        // ...
    };
    
    return $calculator;
}

$calculator = createCalculator(); // 正确