javascript - Mobx:Observable 数组显示不正确

Question

我想了解如何在 Mobx 中使用可观察数组。

我很难弄清楚这是为什么:

let entities = observable([]);
entities[0] = "foo";
autorun(() =>{
  console.log(entities);
});

写道:

[$mobx: Object]
0: (...)
1: (...)
2: (...)
3: (...)
4: (...)
5: (...)
6: (...)
7: (...)
8: (...)
9: (...)
10: (...)
11: (...)
12: (...)
13: (...)
14: (...)
15: (...)
16: (...)
17: (...)
...
999: (...)

而不是经典数组？

Answer 1

搞清楚!

如文档中所述

Bear in mind that Array.isArray(observable([])) will yield false, so whenever you need to pass an observable array to an external library, it is a good idea to create a shallow copy before passing it to other libraries or built-in functions (which is good practice anyway) by using array.slice() or array.peek(). So Array.isArray(observable([]).slice()) will yield true.

文档示例向我们展示了一个 todos.filter()，这可能会导致混淆，因为 todos 看起来像一个真正的 JS 数组。但事实并非如此。

因此，为了让我的示例正常工作，我只需要 console.log(entities.slice()) 即可显示真正的 JS 数组。