Question

php类方法中参数问题，参数怎么是一个类名 加上变量，怎么理解？

class Test
{
private $foo;

public function __construct($foo)
{
$this->foo = $foo;
}

private function bar()
{
echo 'Accessed the private method.';
}

public function baz(Test $other)
{
// We can change the private property:
$other->foo = 'hello';
var_dump($other->foo);

// We can also call the private method:
$other->bar();
}
}

$test = new Test('test');

$test->baz(new Test('other'));

Answer 1

同强类型语言,限制参数只能是该类或者该类的子类的实例

Answer 2

 public function baz(Test $other) 么?

这是限定 $other 参数只能是 Test 类型,  类型限定.