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I'd like to filter out objects which do not have an ext key on them

How can I remove objects which do not have an ext key? I want to take pictures, but there is a problem because some objects do not have a picture. I'm confused about filtering. Can it be done with reduce or filter?
{
"posts": [
{
"filename": "1647706792183",
"ext": ".png",
"w": 300,
"h": 450,
"tn_w": 166,
"tn_h": 250,
"tim": 1664328637690788,
"time": 1664328637,
"md5": "Omk9VtmPOD1U38U1OOAP/w==",
"fsize": 200271,
"resto": 0,
"country": "DK",
"bumplimit": 0,
"imagelimit": 0,
"semantic_url": "f1-relentless-formula-one-general-all-smiles",
"replies": 378,
"images": 155,
"unique_ips": 102,
"tail_size": 50
},
{
"now": "09/27/22(Tue)21:31:17",
"name": "Anonymous",
"resto": 123946553,
}
]
}

You can use .filter to run a function that returns true/false for each item of your data.
const data = { posts: [ .... ] };
const postsWithExt = data.posts.filter(post => post.ext !== undefined);
If you want to filter falsy values for .ext then use
posts.filter(post => !post.ext)

You can just filter your posts array where the ext property exists.
e.g.
const data = {
"posts": [{
"filename": "1647706792183",
"ext": ".png",
"w": 300,
"h": 450,
"tn_w": 166,
"tn_h": 250,
"tim": 1664328637690788,
"time": 1664328637,
"md5": "Omk9VtmPOD1U38U1OOAP/w==",
"fsize": 200271,
"resto": 0,
"country": "DK",
"bumplimit": 0,
"imagelimit": 0,
"semantic_url": "f1-relentless-formula-one-general-all-smiles",
"replies": 378,
"images": 155,
"unique_ips": 102,
"tail_size": 50
},
{
"now": "09/27/22(Tue)21:31:17",
"name": "Anonymous",
"resto": 123946553,
}
]
};
const result = data.posts.filter(x => x.ext);
console.log(result);

Converting one data structure to another

Hi I need to parse some structure to to show some data in line chart. I have this data structure , and I need to convert it for array example_output:
data = {
"el1": [{
"date": "2017.01",
"data1": {
"series_1": {
"a": 10,
"b": 20,
"c": 50,
"d": 15,
"e": 8
},
"Series_2": {
"yes": 5,
"no": 3
},
"Series_3": {
"s": 2,
"n": 9
}
},
"text": [{
"t": "header",
"c": "text"
}, {
"t": "header2",
"c": "text2"
}]
}, {
"date": "2017.02",
"data1": {
"series_1": {
"a": 56,
"b": 23,
"c": 45,
"d": 69,
"e": 14
},
"Series_2": {
"yes": 2,
"no": 1
},
"Series_3": {
"s": 6,
"n": 4
}
},
"text": [{
"t": "header",
"c": "text"
}, {
"t": "header2",
"c": "text2"
}]
}, {
"date": "2017.03",
"data1": {
"series_1": {
"a": 15,
"b": 12,
"c": 10,
"d": 54,
"e": 4
},
"Series_2": {
"yes": 20,
"no": 16
},
"Series_3": {
"s": 9,
"n": 7
}
},
"text": [{
"t": "header",
"c": "text"
}, {
"t": "header2",
"c": "text2"
}]
}
]
};
and I need OUTPUT like this for chartist.js
var example_output = [{
labels: ['2017.01', '2017.02', '2017.03'],
series: {
[10, 56, 15],
[20, 23, 12],
[50, 45, 10],
[15, 69, 54],
[8, 14, 4]
},
labels: ['2017.01', '2017.02', '2017.03'],
series: {
[5, 2, 20],
[3, 1, 16]
},
labels: ['2017.01', '2017.02', '2017.03'],
series: {
[2, 6, 9],
[9, 4, 7]
},}] ;
Please compare digits from the original and the example_output to better understand how this should look like. I use code for parse this but someting goes wrong:
function parseData(data) {
var _newData = {};
var allSeries = [];
data.elements.forEach(function(el){
_newData[el.date] = el.info
if(allSeries.length==0)
allSeries = Object.keys(el.info);
});
return allSeries.map(function(el) {
var obj = {
labels: [],
series: []
};
obj.labels = Object.keys(_newData);
Object.keys(_newData).forEach(function(_el) {
obj.series.push(Object.values(_newData[_el][el]));
});
var _newSeries = [];
obj.series[0].forEach(function(el, i){
_newSeries.push([el, obj.series[1][i]]);
});
obj.series = _newSeries;
return obj;
});
}

You can use array#forEach and array#reduce. Use first loop to iterate through el1 and then use reduce for the series key and accumulate the result in the output_example.
NOTE: The series in your output is incorrect. It should be an array instead of object.
const data = {"el1": [{"date": "2017.01","data1": {"series_1": {"a": 10,"b": 20,"c": 50,"d": 15,"e": 8},"Series_2": {"yes": 5,"no": 3},"Series_3": {"s": 2,"n": 9}},"text": [{"t": "header","c": "text"}, {"t": "header2","c": "text2"}]}, {"date": "2017.02","data1": {"series_1": {"a": 56,"b": 23,"c": 45,"d": 69,"e": 14},"Series_2": {"yes": 2,"no": 1},"Series_3": { "s": 6,"n": 4 }},"text": [{"t": "header","c": "text"}, {"t": "header2","c": "text2"}]}, {"date": "2017.03","data1": {"series_1": {"a": 15,"b": 12,"c": 10,"d": 54,"e": 4},"Series_2": {"yes": 20, "no": 16},"Series_3": {"s": 9, "n": 7}},"text": [{"t": "header","c": "text"}, {"t": "header2","c": "text2" }]}]};
transpose = (arr) => arr.reduce((r,v,i) => {
(r[i] = r[i] || []).push(v);
return r;
},[]);
let example_output = [];
data.el1.forEach((o) => {
Object.keys(o.data1).reduce((r, k, i) => {
r[i] = r[i] || {};
if('labels' in r[i])
r[i]['labels'].push(o.date);
else
r[i]['labels'] = [o.date];
if('series' in r[i])
Object.values(o.data1[k]).forEach((v,j) => r[i]['series'][j].push(v));
else
r[i]['series'] = transpose(Object.values(o.data1[k]));
return r;
},example_output);
},[]);
console.log(example_output);
.as-console-wrapper { max-height: 100% !important; top: 0; }

Normalise JSON object key names

I am wanting to write a function to turn a JSON object's keys into more appropriate names. As you can see by the JSON object below, the keys are 1 letter and are not very readable or useful for anyone. Therefore I would like to loop through the object (or something similar) and rename all the keys, and then return this JSON.
{
"e": "56049",
"pp": "371861",
"c": "GAME",
"x": 2,
"st": "2017-04-27T15:01:29Z",
"o": 0,
"r": true,
"u": "2017-04-27T15:01:29Z",
"t": "p",
"i": "371871",
"z": 1493305289586
}

You can reduce object keys to new object, e.g.:
const obj = {
"e": "56049",
"pp": "371861",
"c": "GAME",
"x": 2,
"st": "2017-04-27T15:01:29Z",
"o": 0,
"r": true,
"u": "2017-04-27T15:01:29Z",
"t": "p",
"i": "371871",
"z": 1493305289586
}
// [key] -> [normalized name] mapping
const names = {
"e": "e-name",
"pp": "pp-name",
"c": "c-name",
"x": "x-name",
"st": "st-name",
"o": "o-name",
"r": "r-name",
"u": "u-name",
"t": "t-name",
"i": "i-name",
"z": "z-name"
}
const renamedProps = Object.keys(obj).reduce((renamed, key) => {
renamed[names[key]] = obj[key];
return renamed;
}, {});

var obj = {
"e": "56049",
"pp": "371861",
"c": "GAME",
"x": 2
},
names = ["e_new-name", "pp_new-name", "c_new-name", "x_new-name"],
updated = {},
keys = Object.keys(obj);
for (i = 0; i < keys.length; i++) {
updated[names[i]] = obj[keys[i]];
}
console.log(JSON.stringify(updated));
// will print
// {"e_new-name":"56049","pp_new-name":"371861","c_new-name":"GAME","x_new-name":2}
jsfiddle

Generating dictionaries and lists in JavaScript after a JSON

I'm receiving a JSON in this format:
{
"0": {
"a": 0.0,
"b": 1.0,
"G": 6.0,
"w": 0.0,
"F": -1.0
},
"1": {
"a": 0.0,
"b": 0.1429004669189453,
"G": 0.000301361083984375,
"w": 0.1429004669189453,
"F": -1.0
},
"2": {
"a": 0.0,
"b": 0.1429004669189453,
"G": 0.000301361083984375,
"w": 0.1429004669189453,
"F": -1.0
},
"3": {
"a": 0.0,
"b": 0.1429004669189453,
"G": 0.000301361083984375,
"w": 0.1429004669189453,
"F": -1.0
....
Let's say I call that a json variable. I'm trying to turn it into something like:
[
{"key": "series1",
values: [
[`json`["1"]["a"],`json`["1"]["F"]],[`json`["1"]["b"],`json`["1"]["G"]]
]
},
{"key": "series2",
values: [
[`json`["2"]["a"],`json`["2"]["F"]],[`json`["2"]["b"],`json`["2"]["G"]]
]
},
{"key": "series3",
values: [
[`json`["3"]["a"],`json`["3"]["F"]],[`json`["3"]["b"],`json`["3"]["G"]]
]
},
....
]
I tried this JavaScript for accomplishing it but got lost :S
var data = function myData(json) {
series = {}
for (iteracion in json) {
series.push({
key: iteracion, values: [[x: iteracion['a'], y: iteracion['F']],[x: iteracion['b'], y: iteracion['G']]]
})
}
return series

A solution to your problem is:
var result = [];
for (var series in json) {
result.push({
key : 'series' + series,
values : [
json[series].a,
json[series].F,
json[series].b,
json[series].G,
]
});
}
If you don't really need an array of objects that contain a key and a value, i organized your information slightly better:
var result = {};
for (var series in json) {
result['series' + series] = [
json[series].a,
json[series].F,
json[series].b,
json[series].G,
];
}
This results in something like this:
{
series0 : [ 0, -1, 1, 6 ],
series1 : [ 0, -1, 0.14, 0.0003],
...
}

How to get image url

If I parse a Tweet from the Twitter API using:
tweet.entities.media
I get the below json. But how would I access media_url property? Its nested in a really difficult place inside the json object.
tweet.entities.media[0].media_url
returns an error.
{
"image": [
{
"id": 511403875438301200,
"id_str": "511403875438301185",
"indices": [
44,
66
],
"media_url": "http://some_url.jpg",
"media_url_https" : "https: //some_url.jpg",
"url": "http://whatever.com",
"display_url": "pic.twitter.com/BNIPh3ZlRD",
"expanded_url": "https://twitter.com/some_url/1",
"type": "photo",
"sizes": {
"thumb": {
"w": 150,
"h": 150,
"resize": "crop"
},
"small": {
"w": 680,
"h": 482,
"resize": "fit"
},
"large": {
"w": 2048,
"h": 1453,
"resize": "fit"
},
"medium": {
"w": 1200,
"h": 851,
"resize": "fit"
}
}
}
]
}

how would I access media_url?
It appears to me that you are just missing image[0]:
tweet.entities.media.image[0].media_url
$(document).ready(function() {
var tweet = jQuery.parseJSON( '{"entities":{"media":{"image":[{"id":511403875438301200,"id_str":"511403875438301185","indices":[44,66],"media_url":"http://pbs.twimg.com/media/BxjfHXxCEAETmig.jpg","media_url_https":"https: //pbs.twimg.com/media/BxjfHXxCEAETmig.jpg","url":"http://whatever.com","display_url":"pic.twitter.com/BNIPh3ZlRD","expanded_url":"https://twitter.com/AWish4Me/status/511403876642463744/photo/1","type":"photo","sizes":{"thumb":{"w":150,"h":150,"resize":"crop"},"small":{"w":680,"h":482,"resize":"fit"},"large":{"w":2048,"h":1453,"resize":"fit"},"medium":{"w":1200,"h":851,"resize":"fit"}}}]}}}');
document.body.innerHTML = tweet.entities.media.image[0].media_url;
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

I think I got it.
It was breaking because some of the Tweets didn't have images..
I had to check for empty properties...
return {"image_url":(tweet.entities.media!==undefined)?((tweet.entities.media[0]!=="")?(tweet.entities.media[0].media_url):('')): ('') };