> 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/grammar/op/unary.md).

# unary operator

[JS](/web/js.md) ⟩ [statement](/web/js/grammar/statement.md) ⟩ [expression](/web/js/grammar/statement/expr.md) ⟩ [operator](/web/js/grammar/op.md) ⟩ unary

{% hint style="success" %}
([operator](/web/js/grammar/op.md)) an operation with <mark style="color:yellow;">**only 1 operand**</mark>.  :point\_right: [table of operators](/web/js/grammar/op/table-of-operators.md)&#x20;
{% endhint %}

{% tabs %}
{% tab title="🔴 主題" %}

* [delete](/web/js/val/obj/prop/create/delete.md) - delete object property.
* [void](/web/js/grammar/op/unary/void.md) - discards an expression's return value.
* [typeof](/web/js/val/type/name/typeof.md) - determines the type of a value.
* [await](/web/js/async/await.md) -&#x20;
* [`+`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Unary_plus) - unary plus operator converts its operand to Number type.
* [`-`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Unary_negation) - unary negation operator converts its operand to Number type and then negates it.
* [`~`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT) - bitwise NOT operator.
* [`!`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_NOT) - logical NOT operator.
  {% endtab %}

{% tab title="👥 相關" %}

* [binary operator](/web/js/grammar/op/binary.md)
* [ternary operator](/web/js/grammar/op/ternary.md)
  {% endtab %}

{% tab title="📘 手冊" %}

* [unary operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators#unary_operators)
  {% endtab %}
  {% endtabs %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://lochiwei.gitbook.io/web/js/grammar/op/unary.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.