### 一元運算符 一元運算符只有一個操作數. - [`delete`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/delete) `delete` 運算符用來刪除對象的屬性. - [`void`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/void) `void` 運算符表示表達式放棄返回值. - [`typeof`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/typeof) `typeof` 運算符用來判斷給定對象的類型. - [`+`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Unary_plus) 一元加運算符將操作轉換為Number類型. - [`-`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Unary_negation) 一元減運算符將操作轉換為Number類型并取反. - [`~`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators#Bitwise_NOT) 按位非運算符. - [`!`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_Operators#Logical_NOT) 邏輯非運算符.