23 lines
640 B
Markdown
23 lines
640 B
Markdown
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---
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title: Use Closure to Protect Properties Within an Object from Being Modified Externally
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localeTitle: 使用闭包保护对象内的属性不被外部修改
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---
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## 使用闭包保护对象内的属性不被外部修改
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### 方法
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就像在给出的示例中一样，不是使用`this`关键字声明`weight`变量，而是必须使用`let`关键字将其声明为私有变量。这样它只能在`Bird`函数内访问。然后必须在`Bird`函数内添加`getWeight`方法以访问`weight`变量。
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### 解
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```javascript
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function Bird() {
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let weight = 15;
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this.getWeight = function() {
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return weight;
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};
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}
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```
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