问题

以下是已经翻译好的内容：

我试图获取由外部应用程序添加的元素。我能够获取这个特定的元素的唯一方法是通过data-i18n-key属性，我以为我可以像获取任何数据属性一样获取它，就像这样。

这段代码：

```javascript
const buttons = document.querySelectorAll('[data-i18n-key="sdk.seamless_product_reward.paid_items_required"]');
console.log(buttons.length);

然而，这并没有返回任何内容。有没有办法可以做到这一点？

<details>
<summary>英文:</summary>

I&#39;m trying to get an element which is added by an external application. The only way I can get this specific element is by the data-i18n-key attribute which I thought I can grab like any data attribute so something like this.

The code:

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    const buttons = document.querySelectorAll(&#39;[data-i18n-key=&quot;sdk.seamless_product_reward.paid_items_required&quot;]&#39;);
    console.log(buttons.length);

&lt;!-- language: lang-html --&gt;

    &lt;span class=&quot;lion-reward-item__redeem-button-text lion-loyalty-page-reward-item__redeem-button-text&quot; data-i18n-key=&quot;sdk.seamless_product_reward.paid_items_required&quot;&gt;Paid items required&lt;/span&gt;

&lt;!-- end snippet --&gt;

However, this doesn&#39;t return anything. Any ideas how to do this?

</details>


# 答案1
**得分**: 1

当然，Barmer是绝对正确的。你的代码有效。问题在于你的JS在DOM完成加载之前就被初始化了。将你的JS放在闭合的`</body>`标签之上。

<details>
<summary>英文:</summary>

Of course, Barmer is absolutely right. Your code works. The problem will be that your JS is initialised before the DOM has finished loading. Pack your JS above the closing body tag.

</details>