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Code Issues Releases Wiki Activity

docs(object): fix #1004

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ruanyf 2020-09-02 00:53:24 +08:00
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docs/object.md
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@ -885,7 +885,7 @@ const showSplashScreen = response.settings.showSplashScreen ?? true;
const animationDuration = response.settings?.animationDuration ?? 300;
```
上面代码中，`response.settings`如果是`null`或`undefined`，就会返回默认值300。
上面代码中，如果`response.settings`是`null`或`undefined`，或者`response.settings.animationDuration`是`null`或`undefined`，就会返回默认值300。也就是说，这一行代码包括了两级属性的判断。
这个运算符很适合判断函数参数是否赋值。