Tengo el siguiente JSON, ¿cómo obtengo la diferencia entre la fecha anterior para num_followers para cada sitio web?
me gusta para el sitio web yqq el 15-02-2022 Necesito obtener la diferencia entre num_followers del 14-02-2022 y actualizar num_followers con valor de diferencia
[ { "date": "2022-02-15", "websites": [ { "website_name": "yqq", "num_followers": "454421" }, { "website_name": "soundcloud", "num_followers": "757127" }, { "website_name": "twitter", "num_followers": "21779161" }, { "website_name": "soundcloud", "num_followers": "757054" }, { "website_name": "triller", "num_followers": "5196" }, ] }, { "date": "2022-02-14", "websites": [ { "website_name": "yqq", "num_followers": "123058219" }, { "website_name": "triller", "num_followers": "5195" }, { "website_name": "tiktok", "num_followers": "17100000" }, { "website_name": "instagram", "num_followers": "123059626" }, { "website_name": "tiktok", "num_followers": "17100000" }, { "website_name": "tiktok", "num_followers": "17100000" }, { "website_name": "soundcloud", "num_followers": "756956" }, ] } ]Seguir me funcionó gracias a @Bravo
rdiff = []; for (var k = 0; k < r.length; k++) { if (typeof r[k + 1] != 'undefined') { var differences = r[k].websites.map(function (_ref) { var _r$websites$find; var website_name = _ref.website_name, num_followers = _ref.num_followers, website_id = _ref.website_id; return { website_name: website_name, website_id: website_id, num_followers: num_followers - (((_r$websites$find = r[k + 1].websites.find(function (_ref2) { var x = _ref2.website_name; return x === website_name; })) === null || _r$websites$find === void 0 ? void 0 : _r$websites$find.num_followers) || 0) }; }); // console.log(differences); diff = { "date": r[k].date, "websites": differences } rdiff.push(diff); } } // console.log(rdiff);