1. 簡(jiǎn)介

終于騰出一點(diǎn)時(shí)間來解決近段時(shí)間遺留的問題，前幾天有位同學(xué)在Easyswoole下提了一個(gè)issue。因此做了幾個(gè)case 用來驗(yàn)證

PHP 7.4.0 (cli) (built: Dec  6 2019 23:00:14) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies

2. Case

不約束類型,不賦初值

class Test
{
    public $name;
}

$obj = new Test();

$format = "【%s】==>【%s】";
foreach ($obj as $key => $value)
{
    $res = sprintf($format, $key, $value);
    var_dump($res);
}

結(jié)果

string(19) "【name】==>【】"

不約束類型,賦初值

class Test
{
    public $name='zhangsan';
}

$obj = new Test();

$format = "【%s】==>【%s】";
foreach ($obj as $key => $value)
{
    $res = sprintf($format, $key, $value);
    var_dump($res);
}

結(jié)果

string(27) "【name】==>【zhangsan】"

約束類型,不賦初值

class Test
{
    public string $name;
}

$obj = new Test();
var_dump($obj);
$format = "【%s】==>【%s】";
foreach ($obj as $key => $value)
{
    $res = sprintf($format, $key, $value);
    var_dump($res);
}

結(jié)果

啥也沒有,把$obj 打印出來, 循環(huán)不到
object(Test)#1 (0) {
  ["name"]=>
  uninitialized(string)
}

約束類型,賦初值

class Test
{
    public string $name='zhangsan';
}

$obj = new Test();
var_dump($obj);
$format = "【%s】==>【%s】";
foreach ($obj as $key => $value)
{
    $res = sprintf($format, $key, $value);
    var_dump($res);
}

結(jié)果

string(27) "【name】==>【zhangsan】"

結(jié)論

對(duì)于之前的版本是都能拿到的,但7.4定義有約束類型屬性時(shí)且不賦初始值的情況下是拿不到的。