我可以定义具有索引签名的Typescript类吗? [英] Can I define a Typescript class which has an index signature?

问题描述

我有一个名为IRawParams的接口类型，该接口类型仅指定了string键和any值.

I have an interface type called IRawParams which simply specifies a string key and any vals.

interface IRawParams {
    [key: string]: any
}

我有一个类，ParamValues，其中包含一些在键/值之上的行为.我想指定ParamValues类实现IRawParams接口.

I have a class, ParamValues which contains some behavior on top of keys/values. I'd like to specify that the ParamValues class implements IRawParams interface.

class ParamValues implements IRawParams {
    parseFromUrl(urlString: string) {
        Parser.parse(urlString).forEach(item => this[item.key] = item.val);
    }
}

// so I can do something like this
var params = new ParamValues();
params.parseFromUrl(url);
var userId = params.userId;

尝试此操作时，出现编译器错误:

When I attempt this, I get a compiler error:

错误TS2420:类'ParamValues'错误地实现了接口'IRawParams'. 类型'ParamValues'中缺少索引签名.

error TS2420: Class 'ParamValues' incorrectly implements interface 'IRawParams'. Index signature is missing in type 'ParamValues'.

我可以让我的类实现IRawParams接口，还是让Typescript允许我的类的实例与索引类型{[key: string]: any}兼容?

Can I get my class to implement the IRawParams Interface, or otherwise get Typescript to allow instances of my class to be compatible with an indexed type {[key: string]: any}?

推荐答案

要定义具有索引签名的类，只需在该类中编写索引签名:

To define a class with an index signature, just write the index signature in the class:

interface IRawParams {
    [key: string]: any
}

class Foo implements IRawParams {
    [k: string]: any;
}

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