How to get json object using key in typescript?

Question

I am newbie in typescript so not really good in syntax.

My requirement is I want to get some specific elment from json file in typescript.

Following is piece of code that I am trying here.

Json file

{
"Description": "data",
"data_list": {
  "example1": {
    "description": "example1",
    "anothermap":{
       "a": "1",
       "b": "2"
    }
 },
 "example2": {
    "description": "example2"
 }
}

}

Typescript file

import * as test from '../test.json';

export class Demo extends cdk.Stage {

  constructor(scope: cdk.Construct, id: string, name: string) {
    super(scope, id);

    #const tskData = test.data_list['example1'];
    const tskData = test.data_list[name];
}

in the above example when I try to call json value using literals then it works but not with varible. I can't use any literal here becuase what system needed will come as input.

Following is the error that I am getting it

Element implicitly has an 'any' type because expression of type 'string' can't be used to index type '

Any help on this would be appriciated

Error when trying to acccess another map : Property 'anothermap' does not exist on type '{ description: string; — keepmoving
– keepmoving, Commented Mar 2, 2022 at 12:37

Adam · Accepted Answer · 2022-03-02 11:02:07Z

1

Typescript determines the json's type from it's structure.

You're trying to index test.data_list with any string, but not all strings in the world are present as keys in the json. Try changing name's type to name: "example1" | "example2"

Or you can automatically create type for possible name values with type NameType = keyof typeof test.data_list; and then simply write name: NameType.

answered Mar 2, 2022 at 11:02

Adam

211 silver badge5 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

keepmoving Over a year ago

I think this second approach works for me and able to access json data as varible. But my example wasn't simple as I paste here so edit it again.

keepmoving Over a year ago

json has been edit and now facing another issue while access another map inside the element. Can you help me on this ?

Adam Over a year ago

Sorry, I thought I could help because I faced a similar issue, but I will leave this to someone more qualified.

Collectives™ on Stack Overflow

How to get json object using key in typescript?

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related