PHP获取对象属性的三种方法

今天查看yii源码，发现yii\base\Model中的attribute()方法是通过反射获取对象的public non-static属性。记得以前看到的代码都是用get_object_vars()这个函数获取的，昨天查看php文档，发现还可以用foreach遍历对象属性。于是写个例子练习下。

class TestClass {
    private $a;
    protected $b;
    public $c;
    public $d;
    public static $e;

    private function funcA() {

    }

    protected function funcB() {

    }

    public function funcC() {

    }

    public function getPropertyMethodOne() {
        echo "[get_object_vars]", PHP_EOL;
        $vars = get_object_vars($this);
        foreach ($vars as $k => $v) {
            echo $k, ' => ', $v, PHP_EOL;
        }
    }

    public function getPropertyMethodTwo() {
        echo "[foreach object]", PHP_EOL;
        foreach ($this as $k => $v) {
            echo $k, ' => ', $v, PHP_EOL;
        }
    }

    public function getPropertyMethodThree() {
        echo "[reflection]", PHP_EOL;
        $class = new ReflectionClass($this);

        foreach ($class->getProperties(ReflectionProperty::IS_PUBLIC) as $property) {
            if (!$property->isStatic()) {
                echo $property->getName(), ' => ', $property->getValue($this), PHP_EOL;
            }
        }
    }
}

• 测试代码一

$obj = new TestClass();

echo "[get_object_vars]", PHP_EOL;
$vars = get_object_vars($obj);
foreach ($vars as $k => $v) {
    echo $k, ' => ', $v, PHP_EOL;
}

echo "[foreach object]", PHP_EOL;
foreach ($obj as $k => $v) {
    echo $k, ' => ', $v, PHP_EOL;
}

echo "[reflection]", PHP_EOL;
$class = new ReflectionClass($obj);

foreach ($class->getProperties(ReflectionProperty::IS_PUBLIC) as $property) {
    if (!$property->isStatic()) {
        echo $property->getName(), ' => ', $property->getValue($obj), PHP_EOL;
    }
}

输出：

[get_object_vars]
c => 
d => 
[foreach object]
c => 
d => 
[reflection]
c => 
d => 

可见，当着三种方法用在类的外部时，结果是一样的。get_object_vars()和foreach是获取到的是对象的public non-static属性，而通过反射的话则需要手动筛选出public non-static属性。

• 测试代码二

$obj = new TestClass();

$obj->getPropertyMethodOne();
$obj->getPropertyMethodTwo();
$obj->getPropertyMethodThree();

输出

[get_object_vars]
a => 
b => 
c => 
d => 
[foreach object]
a => 
b => 
c => 
d => 
[reflection]
c => 
d => 

可见，get_object_vars()和foreach用在类内部时，private、protected、public的实例属性都能获取到。反射就不用说了，通过手动筛选，各种类型的属性都能获取到。