Using JSON format

It turns out that it is common for APIs to output data in JSON format. JSON(JavaScript Object Notation) format is surprisingly simple - it's basically a stringified version of regular JavaScript object, meaning if we have an object {name: "param", hasPlayed: true}, it's JSON equivalent is '{"name": "param","hasPlayed": false}'. We use JSON.stringify to convert object to JSON and JSON.parse to get back the object from JSON:

Converting JavaScript object to JSON

let player = {
    name: "param",
    hasPlayed: true
};

let outData = JSON.stringify(player);

Converting JSON to JavaScript object

let inData = JSON.parse(outData);