用Typescript声明和初始化一个字典 [英] Declare and initialize a Dictionary in Typescript

问题描述

给定以下代码

interface IPerson {
   firstName: string;
   lastName: string;
}

var persons: { [id: string]: IPerson; } = {
   "p1": { firstName: "F1", lastName: "L1" },
   "p2": { firstName: "F2" }
};

为什么初始化不被拒绝？毕竟，第二个对象没有lastName属性。

Why isn't the initialization rejected? After all, the second object does not have the "lastName" property.

推荐答案

编辑已经修复了最新的TS版本。引用@ Simon_Weaver对OP的帖子的评论：

Edit: This has since been fixed in the latest TS versions. Quoting @Simon_Weaver's comment on the OP's post:

注意：此已被修复（不确定哪个TS版本）。 I
在VS中得到这些错误，正如你所料：索引签名是
不兼容。键入'{firstName：string; }'不能分配键入
'IPerson'。类型{firstName：
string;中缺少属性'lastName' }'。

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显然这在传递初始数据在声明。
我猜这是TypeScript中的一个错误，所以你应该在项目站点上提出一个。

---

Apparently this doesn't work when passing the initial data at declaration. I guess this is a bug in TypeScript, so you should raise one at the project site.

你可以通过分割你的例子来使用类型化的字典在声明和初始化中，如：

You can make use of the typed dictionary by splitting your example up in declaration and initialization, like:

var persons: { [id: string] : IPerson; } = {};
persons["p1"] = { firstName: "F1", lastName: "L1" };
persons["p2"] = { firstName: "F2" }; // will result in an error

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