使用参数作为对象 属性 链的一部分

Using parameters as part of an object property chain

Angular 中,我有如下所示的接口(这不是我的代码):

export interface Vehicles {
    id: number;
    cars: Car;
    trucks: Truck;
}

Export interface Car {
    make: number;
    model: number;
}

Export interface Truck {
    make: number;
    model: number;
}

我的服务包含两个函数 doCarMath()doTruckMath(),它们根据 API 的返回值进行计算:

vehicleNumbers: Vehicles;

constructor(private http: HttpClient) {
    this.vehicleNumbers = {};
}

callID(id: string): Observable<Vehicles>{
    return this.http.get<Vehicles>(this.myURL+`/${id}`);
}

getMyCarNumbers(id) {
    this.callID(id).subscribe(results =>
    {
        this.vehicleNumbers = results;
    }
}

doCarMath(): number {
    return this.vehicleNumbers.car.make; / this.vehicleNumbers.car.model;
}

doTruckMath(): number {
    return this.vehicleNumbers.truck.make; / this.vehicleNumbers.truck.model;
}

我想通过传入一个参数来指定 cartruck,将 doCarMath()doTruckMath() 组合成一个 doMath() 函数,像这样:

doMath(p_vehicle): number {
    return this.vehicleNumbers.p_vehicle.make/this.vehicleNumbers.p_vehicle.model; // can p_vehicle be used here?
}

这里如何使用参数p_vehicle?以上为 p_vehicle 参数抛出智能感知错误,但我本地没有代码,无法共享错误。

我认为这可以完成工作:

doMath(p_vehicle): number {
    return this.vehicleNumbers[p_vehicle].make/this.vehicleNumbers[p_vehicle].model; 
}

那么调用该函数将是:

doMath('car'); // or this.doMath('car');
doMath('truck'); // or this.doMath('truck');