我可以定义一个具有索引签名的 Typescript 类吗？
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Can I define a Typescript class which has an index signature?
提问by Chris T
I have an interface type called IRawParamswhich simply specifies a stringkey and anyvals.
我有一个名为的接口类型IRawParams，它只是指定一个string键和值any。
interface IRawParams {
[key: string]: any
}
I have a class, ParamValueswhich contains some behavior on top of keys/values. I'd like to specify that the ParamValuesclass implements IRawParamsinterface.
我有一个类，ParamValues其中包含键/值之上的一些行为。我想指定ParamValues该类实现IRawParams接口。
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;
When I attempt this, I get a compiler error:
当我尝试这样做时，我收到一个编译器错误：
error TS2420: Class 'ParamValues' incorrectly implements interface 'IRawParams'. Index signature is missing in type 'ParamValues'.
错误 TS2420：“ParamValues”类错误地实现了“IRawParams”接口。“ParamValues”类型中缺少索引签名。
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}?
我可以让我的类实现 IRawParams 接口，或者以其他方式获取 Typescript 以允许我的类的实例与索引类型兼容{[key: string]: any}吗？
回答by Ryan Cavanaugh
To define a class with an index signature, just write the index signature in the class:
要定义带有索引签名的类，只需在类中写入索引签名即可：
interface IRawParams {
[key: string]: any
}
class Foo implements IRawParams {
[k: string]: any;
}
