php - 对所有对象属性进行 foreach

Question

如何从该类内部或外部对一个类的所有字段执行 foreach？例如，给定以下类:

class Foo
{
    public $a;
    public $b;
    private $c;
    private $d;

    public function __construct($params)
    {
        foreach($params as $k=>$v){
            $this->$k = $v;
        }
    }

    public function showAll()
    {
        $output = array();
        foreach (this as $k=>$v) {    // How to refer to all the class properties?
            $output[$k] = $v;
        }
        return $output;
    }

}

foreach() 怎么可能？在 showAll()方法引用$a , $b , $c , 和 $d特性？

就此而言，可以从类外获取所有公共(public)属性吗？

$params = array();
$foo = new Foo($params);

foreach ($foo->allProperties as $f=>$v) {    // how to do this?
    echo "{$f}: {$v}\n";
}

Answer 1

自 PHP4 起，您可以使用 get_object_vars 迭代对象的公共(public)属性。

foreach (get_object_vars($foo) as $f => $v) {
    echo "{$f}: {$v}\n";
}

自 PHP5 起 you can直接遍历对象:

foreach ($foo as $f => $v) {
    echo "{$f}: {$v}\n";
}