> For the complete documentation index, see [llms.txt](https://lochiwei.gitbook.io/web/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://lochiwei.gitbook.io/web/js/err/syntax/unexpected-number.md).

# unexpected number❗️

[JS](/web/js.md) ⟩ [error](/web/js/err.md) ⟩ [SyntaxError](/web/js/err/syntax.md) ⟩ unexpected number:exclamation:

{% hint style="danger" %}
⛔ [<mark style="color:red;">**SyntaxError**</mark>](/web/js/err/syntax.md)：[<mark style="color:yellow;">**unexpected number**</mark>](/web/js/err/syntax/unexpected-number.md):exclamation:
{% endhint %}

{% tabs %}
{% tab title="💈範例" %}

* replit：[dot notation](https://replit.com/@pegasusroe/dot-notation#index.js)

```javascript
// object
let obj = {};

// ⭐️ dot notaton
obj.$1 = 'joe';       // ✅ valid identifier
obj.var = 'OK';       // ✅ reserved word is allowed❗

// --------------------------------------------
// obj.1 = 'bad';     // ❌ invalid identifier
//    ^^
// ⛔ SyntaxError: Unexpected number
// --------------------------------------------
```

{% endtab %}

{% tab title="✨ 範例" %}

* [dot notation (.)](/web/js/val/obj/prop/access/dot-notation-..md)
  {% endtab %}
  {% endtabs %}