Typescript : Property does not exist on type 'object'

Question

I have the follow setup and when I loop through using for...of and get an error of :

Property "country" doesn't exist on type "object".

Is this a correct way to loop through each object in array and compare the object property value?

let countryProviders: object[];  export function GetAllProviders() {    allProviders = [       { region: "r 1", country: "US", locale: "en-us", company: "co 1" },       { region: "r 2", country: "China", locale: "zh-cn", company: "co 2" },       { region: "r 4", country: "Korea", locale: "ko-kr", company: "co 4" },       { region: "r 5", country: "Japan", locale: "ja-jp", company: "co 5" }    ]     for (let providers of allProviders) {       if (providers.country === "US") { // error here          countryProviders.push(providers);       }    } } 

Answer 1

You probably have allProviders typed as object[] as well. And property country does not exist on object. If you don't care about typing, you can declare both allProviders and countryProviders as Array<any>:

let countryProviders: Array<any>; let allProviders: Array<any>; 

If you do want static type checking. You can create an interface for the structure and use it:

interface Provider {     region: string,     country: string,     locale: string,     company: string }  let countryProviders: Array<Provider>; let allProviders: Array<Provider>; 

Answer 2

If your object could contain any key/value pairs, you could declare an interface called keyable like :

interface keyable {     [key: string]: any   } 

then use it as follows :

let countryProviders: keyable[]; 

or

let countryProviders: Array<keyable>; 

For your specific case try to define the key type and use Record utility to define the object :

type ProviderKey="region" | "country" | "locale" | "company"  let countryProviders: Array<Record<ProviderKey,string>>;