doc: update javascript.md (#243)
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jaywcjlove
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@ -1191,7 +1191,9 @@ myCat.name = 'Yankee';
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```
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### Proxy
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Proxy 对象用于创建一个对象的代理，从而实现基本操作的拦截和自定义（如属性查找、赋值、枚举、函数调用等）。
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```javascript
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// 用于拦截对象的读取属性操作。
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const handler = {
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@ -1209,36 +1211,43 @@ console.log('c' in p, p.c); // false, 37
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```
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#### 语法
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```javascript
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const p = new Proxy(target, handler)
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```
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- target 要使用 Proxy 包装的目标对象（可以是任何类型的对象，包括原生数组，函数，甚至另一个代理）。
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- handler 一个通常以函数作为属性的对象，各属性中的函数分别定义了在执行各种操作时代理 p 的行为。
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#### 方法
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:- | :-
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:- | :-
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`Proxy.revocable()` | 创建一个可撤销的Proxy对象。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/revocable)
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`Proxy.revocable()` | 创建一个可撤销的Proxy对象 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/revocable)
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#### handler 对象的方法
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:- | :-
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:- | :-
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`handler.getPrototypeOf()`|Object.getPrototypeOf 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/getPrototypeOf)
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`handler.setPrototypeOf()`|Object.setPrototypeOf 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/setPrototypeOf)
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`handler.isExtensible()`|Object.isExtensible 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/isExtensible)
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`handler.preventExtensions()`|Object.preventExtensions 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/preventExtensions)
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`handler.getOwnPropertyDescriptor()`|Object.getOwnPropertyDescriptor 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/getOwnPropertyDescriptor)
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`handler.defineProperty()`|Object.defineProperty 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/defineProperty)
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`handler.has()`|in 操作符的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/has)
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`handler.get()`|属性读取操作的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/get)
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`handler.set()`|属性设置操作的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/set)
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`handler.deleteProperty()`|delete 操作符的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/deleteProperty)
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`handler.ownKeys()`|Object.getOwnPropertyNames 方法和 Object.getOwnPropertySymbols 方法的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/ownKeys)
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`handler.apply()`|函数调用操作的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/apply)
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`handler.construct()`|new 操作符的捕捉器。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/construct)
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`handler.getPrototypeOf()` | Object.getPrototypeOf 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/getPrototypeOf)
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`handler.setPrototypeOf()` | Object.setPrototypeOf 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/setPrototypeOf)
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`handler.isExtensible()` | Object.isExtensible 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/isExtensible)
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`handler.preventExtensions()` | Object.preventExtensions 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/preventExtensions)
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`handler.getOwnPropertyDescriptor()` | Object.getOwnPropertyDescriptor 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/getOwnPropertyDescriptor)
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`handler.defineProperty()` | Object.defineProperty 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/defineProperty)
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`handler.has()` | in 操作符的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/has)
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`handler.get()` | 属性读取操作的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/get)
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`handler.set()` | 属性设置操作的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/set)
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`handler.deleteProperty()` | delete 操作符的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/deleteProperty)
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`handler.ownKeys()` | Object.getOwnPropertyNames 方法和 Object.getOwnPropertySymbols 方法的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/ownKeys)
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`handler.apply()` | 函数调用操作的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/apply)
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`handler.construct()` | new 操作符的捕捉器 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/construct)
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<!--rehype:className=style-list-arrow-->
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### Reflect
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Reflect 是一个内置的对象，它提供拦截 JavaScript 操作的方法。这些方法与proxy handlers (en-US)的方法相同。Reflect不是一个函数对象，因此它是不可构造的。
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```javascript
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// 检测一个对象是否存在特定属性
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const duck = {
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@ -1256,21 +1265,23 @@ Reflect.has(duck, 'haircut');
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```
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#### 静态方法
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:- | :-
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:- | :-
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`Reflect.apply(target, thisArgument, argumentsList)` | 对一个函数进行调用操作，同时可以传入一个数组作为调用参数。和 Function.prototype.apply() 功能类似。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/apply)
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`Reflect.construct(target, argumentsList[, newTarget])` | 对构造函数进行 new 操作，相当于执行 new target(...args)。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/construct)
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`Reflect.defineProperty(target, propertyKey, attributes)` | 和 Object.defineProperty() 类似。如果设置成功就会返回 true。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/defineProperty)
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`Reflect.deleteProperty(target, propertyKey)` | 作为函数的delete操作符，相当于执行 delete target[name]。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/deleteProperty)
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`Reflect.get(target, propertyKey[, receiver])` | 获取对象身上某个属性的值，类似于 target[name]。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/get)
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`Reflect.getOwnPropertyDescriptor(target, propertyKey)` | 类似于 Object.getOwnPropertyDescriptor()。如果对象中存在该属性，则返回对应的属性描述符，否则返回 undefined。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/getOwnPropertyDescriptor)
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`Reflect.getPrototypeOf(target)` | 类似于 Object.getPrototypeOf()。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/getPrototypeOf)
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`Reflect.has(target, propertyKey)` | 判断一个对象是否存在某个属性，和 in 运算符 的功能完全相同。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/has)
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`Reflect.isExtensible(target)` | 类似于 Object.isExtensible().[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/isExtensible)
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`Reflect.ownKeys(target)` | 返回一个包含所有自身属性（不包含继承属性）的数组。(类似于 Object.keys(), 但不会受enumerable 影响).[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/ownKeys)
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`Reflect.preventExtensions(target)` | 类似于 Object.preventExtensions()。返回一个Boolean。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/preventExtensions)
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`Reflect.set(target, propertyKey, value[, receiver])` | 将值分配给属性的函数。返回一个Boolean，如果更新成功，则返回true。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/set)
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`Reflect.setPrototypeOf(target, prototype)` | 设置对象原型的函数。返回一个 Boolean，如果更新成功，则返回 true。[#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/setPrototypeOf)
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`Reflect.apply(target, thisArgument, argumentsList)` | 对一个函数进行调用操作，同时可以传入一个数组作为调用参数。和 Function.prototype.apply() 功能类似 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/apply)
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`Reflect.construct(target, argumentsList[, newTarget])` | 对构造函数进行 new 操作，相当于执行 new target(...args) [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/construct)
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`Reflect.defineProperty(target, propertyKey, attributes)` | 和 Object.defineProperty() 类似。如果设置成功就会返回 true [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/defineProperty)
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`Reflect.deleteProperty(target, propertyKey)` | 作为函数的delete操作符，相当于执行 delete target[name] [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/deleteProperty)
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`Reflect.get(target, propertyKey[, receiver])` | 获取对象身上某个属性的值，类似于 target[name] [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/get)
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`Reflect.getOwnPropertyDescriptor(target, propertyKey)` | 类似于 Object.getOwnPropertyDescriptor()。如果对象中存在该属性，则返回对应的属性描述符，否则返回 undefined [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/getOwnPropertyDescriptor)
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`Reflect.getPrototypeOf(target)` | 类似于 Object.getPrototypeOf() [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/getPrototypeOf)
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`Reflect.has(target, propertyKey)` | 判断一个对象是否存在某个属性，和 in 运算符 的功能完全相同 [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/has)
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`Reflect.isExtensible(target)` | 类似于 Object.isExtensible() [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/isExtensible)
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`Reflect.ownKeys(target)` | 返回一个包含所有自身属性（不包含继承属性）的数组。(类似于 Object.keys(), 但不会受enumerable 影响) [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/ownKeys)
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`Reflect.preventExtensions(target)` | 类似于 Object.preventExtensions()。返回一个Boolean [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/preventExtensions)
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`Reflect.set(target, propertyKey, value[, receiver])` | 将值分配给属性的函数。返回一个Boolean，如果更新成功，则返回true [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/set)
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`Reflect.setPrototypeOf(target, prototype)` | 设置对象原型的函数。返回一个 Boolean，如果更新成功，则返回 true [#](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/setPrototypeOf)
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<!--rehype:className=style-list-arrow-->
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JavaScript this 绑定
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----
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