php - 分配中的 "Object of class ... could not be converted to string"

Question

为什么 PHP 认为我想将该对象转换为字符串？

class Class1 {}

class Class2 {
    function __construct( Class1 $class1Obj) {
        $this->$class1Obj = $class1Obj; // -> Catchable fatal error: Object of class Class1 could not be converted to string
    }
}

$class1Obj = new Class1();
$class2Obj = new Class2($class1Obj);

Answer 1

它是一个额外的$吗？那会更好:

$this->class1Obj = $class1Obj;