问题

我正在将代码从v7.4迁移到8.0，并在我的一个页面上遇到了这个错误，但无法解决它。我知道在php v8.0中会遇到这个错误，如迁移文档中所述。

错误：

致命错误：在/homepages/5/d742909641/htdocs/payroll/Payroll/demo/demo/allowance_setup.php的第77行抛出Uncaught Error: 尝试在空值上分配属性"allow_basic"：堆栈跟踪：#0 {main} /homepages/5/d742909641/htdocs/payroll/Payroll/demo/demo/allowance_setup.php的第77行

代码：

$o1->allow_basic = implode("|", $allow_basic);
$o10->allow_basic = implode("|", $allow_basic);

<details>
<summary>英文:</summary>

I was migrating a code from v7.4 to 8.0 and encountered this error on one of my page but was unable to solve it i know in php v8.0 this error will be encountered as written in migrating docs

error:

Fatal error: Uncaught Error: Attempt to assign property "allow_basic" on null in /homepages/5/d742909641/htdocs/payroll/Payroll/demo/demo/allowance_setup.php:77 Stack trace: #0 {main} thrown in /homepages/5/d742909641/htdocs/payroll/Payroll/demo/demo/allowance_setup.php on line 77

Code:

    $o1->allow_basic = implode("|", $allow_basic);
    $o10->allow_basic = implode("|", $allow_basic);

</details>


# 答案1
**得分**: 1

错误信息很明确：

&gt; 尝试在空对象上分配属性 "allow_basic"

在调用 `$o1-&gt;allow_basic` 之前，`$o1` 是空的，这导致了错误。

在使用之前，你必须将 `$o1` 定义为一个 stdClass：

```php
$o1 = new stdClass();
$o1-&gt;allow_basic = 'foo';

在线尝试

请查看有关 stdClass 的 PHP 文档：https://www.php.net/manual/en/class.stdclass.php#stdclass.properties-example

$o1 = new stdClass();
$o1->allow_basic = 'foo';