javascript - How to set objects property not at the same place? -


i have model, lets say:

export interface car {   driverid: string;   drivername: string;   color: string; }

in function want return an array of objects model, can build after few async calls happening in function, wanted declare empty array of model , assign relevant properties have them:

  public getlistofcarobjects(): car[]  {     let listofcars: car[] = [];     self._serviceone.getids().subscribe(       (res: driversinfo) => {         res.ids.map((id: string, idindex: number) => {           listofcars[idindex].driverid = id;           // more stuff api calls below , building object           ...   }

but im getting error:

error typeerror: cannot set property 'driverid' of undefined

how, should this?

thanks!!

you have create object instance @ index referencing. create when receive data, either pushing value or setting index: 

listofcars.push({ driverid: id, dirvername: "", color: "" }); listofcars[idindex] = { driverid: id, dirvername: "", color: "" };

since interface specifies properties required have specify them when creating new object, did above. if create cars anid can mark rest of properties optional:

export interface car {   driverid: string;   drivername?: string;   color?: string; }

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