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description: 🚧 under construction
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# octal literals not allowed in strict mode❗️

[JS](../..) ⟩ [error](..) ⟩ [SyntaxError]() ⟩ delete of an unqualified identifier in strict mode

{% hint style="danger" %}
[<mark style="color:red;">**SyntaxError**</mark>]()<mark style="color:red;">**:**</mark> [<mark style="color:yellow;">**octal literals not allowed in strict mode**</mark>](octal-literals-not-allowed-in-strict-mode):exclamation:
{% endhint %}

{% tabs %}
{% tab title="💈範例" %}
* replit：[octal literals not allowed in strict mode](https://replit.com/@pegasusroe/octal-literals-not-allowed-in-strict-mode#index.js)

```javascript
let x = 010;    // ❗ octal literal
let y = 0x10;   // ⭐ hexadecimal literal

//  mode:    sloppy      strict
// -------------------------------------
x,        // ✅ 8       ⛔ SyntaxError
y,        // ✅ 16      ✅ 16

// ⛔ SyntaxError: Octal literals are not allowed in strict mode.
```
{% endtab %}

{% tab title="👥 相關" %}
* [literal](../../grammar/token/literal "mention")
* [strict-mode](../../concept/env/js-engine/mode/strict-mode "mention")
* [always](../../concept/env/js-engine/mode/strict-mode/always "mention")
{% endtab %}

{% tab title="📗 參考" %}
* [ ] itHome ⟩ [你不可不知的 JavaScript 二三事](https://ithelp.ithome.com.tw/users/20112483/ironman/2016) ⟩&#x20;
  * [ ] [#Day12：看 Strict Mode 如何施展「還我漂亮拳」(1)](https://ithelp.ithome.com.tw/articles/10205275)
{% endtab %}

{% tab title="📘 手冊" %}
*
{% endtab %}

{% tab title="🚧" %}
* [ ] octal literal
{% endtab %}
{% endtabs %}
