“[index：string]" ：打字稿中的IFoo表示法 [英] "[index : string]" : IFoo notation in typescript

问题描述

有人可以告诉我这是什么

Can someone please tell me what the

[index：string]：IFoo 表示

export interface IBar {
   [index : string] : IFoo;
}

export interface IFoo {
        CharacterName: string;
        DisplayName: string;
    }

我查看了Typescript Revealed书，但没有发现任何符号。它应该是实现IFoo的对象集合吗？谢谢。

I looked through the Typescript Revealed book and found nothing on that notation. Is it supposed to be a collection of objects that implement IFoo? Thanks.

推荐答案

它用于显示索引接口实例时的结果类型。当IBar类型的元素由字符串索引，即 [someString]
时，结果将为IFoo类型。
例如：

It is used to show the type of the result when an instance of the interface is indexed. When elements of type IBar are indexed by a string i.e [someString] the result will be of type IFoo. e.g:

export interface IBar {
   [index : string] : IFoo;
}

export interface IFoo {
        CharacterName: string;
        DisplayName: string;
    }


var x:IBar; 
var y=x['asdf']; // Same as var y:IFoo = x['asdf']

更多： http://blogs.msdn.com/b/typescript/archive /2013/01/24/interfaces-walkthrough.aspx 转到标题描述可转换对象

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