CODEWITHSUNDEEP
jsontypescript
Kokodoko
Kokodoko

Reputation: 28128

How to use json with typescript interfaces?

I am reading JSON data in my typescript app. I found this tool JSON2TS that creates interfaces from JSON, so that typescript knows what the json must contain.

My json:

{
"questions": [
    {
    "text": "Is this a question?",
    "answers": ["yes", "no", "maybe", "maybe not"],
    "correct":1
    }]
}

The generated interfaces:

declare module namespace {

export interface Question {
    text: string;
    answers: string[];
    correct: number;
}

export interface RootObject {
    questions: Question[];
}

}

These interfaces need to be saved in a d.ts file and referenced in the code. My question: how do I actually use the json data after loading it with ajax?

Upvotes: 0

Views: 3823

Answers (1)

NYCdotNet
NYCdotNet

Reputation: 4637

With that definition file, if your code is in the namespace namespace, you could do it like this:

var questions = <RootObject>functionThatReturnsYourJSONData().questions;

If your code is not in the namespace namespace, this should work.

var questions = <namespace.RootObject>functionThatReturnsYourJSONData().questions;

In either case, this would be strongly typed:

if (questions.length > 0) {
    console.log(questions[0].text);
}

Upvotes: 1

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