Develop Reference

javascript - convert string to json array

I was using s3 select to fetch selective data and display them on my front end .
I converted array of byte to buffer and then to string like below as string
let dataString = Buffer.concat(records).toString('utf8');
the result i got was string like below
{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"}
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"}
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"}
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"}
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"}
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"}
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"}
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"}
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"}
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"}
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"}
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}
Now i want to convert them to json array , i got a solution like below
let dataArray = dataString.split('\n');
//remove white spaces and commas etc
dataArray = dataArray.filter(d=> d.length >2);
//change string to json
dataArray = dataArray.map(d=> JSON.parse(d));
Now the problem is that i have splitted them with new line and wont work if the json is compressed or data itself can have new line.
What is the best way to handle this situation. i want the output like below
[{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"},
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"},
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"},
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"},
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"},
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"},
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"},
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"},
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"},
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"},
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"},
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}
]

#sumit
please take a look at this solution.
let dataString=`{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"}
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"}
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"}
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"}
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"}
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"}
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"}
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"}
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"}
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"}
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"}
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}`;
let dataArray = dataString.match(/{(?:[^{}]*|(R))*}/g);
dataArray = dataArray.map(d=> JSON.parse(d));
console.log(dataArray);

Yeah, it is not a very good idea to concatenate objects into a string like that. If you don't have any other choice, however, something like that should do the trick:
const initialString = `{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"}
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"}
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"}
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"}
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"}
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"}
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"}
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"}
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"}
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"}
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"}
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}`;
const json = `[${initialString.replace(/}\s*{/g, '},{')}]`;
const array = JSON.parse(json);

How to split into valid array

I've following object that is return from API and I want to convert them into array either in javascript or c#.
[
"1":"h1:first",
"2":".content a > img",
"3":"#content div p"
]
I've tried converting that to json object, split function etc but din't working for me.
It throws exception Uncaught SyntaxError: Unexpected token : while using split function in javascript.

You can convert it to valid JSON by replacing the square brackets with curly braces.
var data = '["1":"h1:first","2":".content a > img","3":"#content div p"]';
var json = `{ ${data.trim().slice(1, -1)} }`;
Then JSON.parse it like you had tried earlier. And if you want an array, and don't care about the actual index numbers, you can use Object.values to get the Array of values.
var data = '["1":"h1:first","2":".content a > img","3":"#content div p"]';
var json = `{ ${data.trim().slice(1, -1)} }`;
console.log(json);
var parsed = JSON.parse(json);
console.log(parsed);
var array = Object.values(parsed);
console.log(array);

I choose c# code to fix the issue instead client-side (as suggested by #rock star below).
string[] domSelectors = selectors.Replace("\"", "").Split(new string[] { "[", ",", "]" }, StringSplitOptions.RemoveEmptyEntries);
foreach (var domSelector in domSelectors)
{
string[] arrayElements = domSelector.Split(':');
string selector = string.Join(":", arrayElements.Skip(1));
}
Hope it helps others who don't have control over API and want to fix the issue as I'd in my project!

Parsing JSON and loading into array

JSON-https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=MSFT&apikey=demo
I am trying to take the JSON from the above link and place it in the following format(date,open,high,low,close)...
[
[1277424000000,38.58,38.61,37.97,38.10],
[1277683200000,38.13,38.54,37.79,38.33],
[1277769600000,37.73,37.77,36.33,36.60],
[1277856000000,36.67,36.85,35.72,35.93],
]
The date does not need to be Epoch time.
My code....
$.getJSON('https://www.alphavantage.co/query?
function=TIME_SERIES_DAILY&symbol=MSFT&apikey=demo', function(data) {
//Get the time series data
var timeseries = data['Time Series (Daily)']
var ohlcarray = [];
//Loop through each time series and convert it to JSON format
$.each(timeseries, function(key, value) {
var ohlcdata=[];
ohlcdata[0]=value[0];//date
ohlcdata[1]=value[1];//open
ohlcdata[2]=value[2];//high
ohlcdata[3]=value[3];//low
ohlcdata[4]=value[4];//low
ohlcarray.push(ohlcdata);
});
console.log(ohlcarray[0]);//test if worked properly
});
The output....
[undefined, undefined, undefined, undefined, undefined]
value[x] returns undefined. Any ideas on why this happens?
Thanks!

The reason is that in the each loop, the value is not a list but an object. To access it, you'd have to grab it using keys.
ohlcdata[0] = key; //date
ohlcdata[1] = value['1. open']; //open
ohlcdata[2] = value['2. high']; //high
ohlcdata[3] = value['3. low']; //low
ohlcdata[4] = value['4. close']; //low
https://jsfiddle.net/koralarts/7c2fkf93/2/

At this point it is already JSON. As Patrick mentioned, getJSON automatically parses json. You will need to access it with the array bracket notation since there are spaces in the property name.
var timeSeries = data['Time Series (Daily)'];
See ex: https://jsfiddle.net/dz0phhn2/6/

set array as value in json format in Javascript

I want to add array as json value.
Json format is as follows.
json_data = [
'name':'Testing'
'email':'TestEmail'
'links':[
'test#test.com',
'test#test1.com',
'test#test3.com']
]
How can I set value of 'links' in javascript like that?
I did as follows.
links_array = [];
links_array =['testing','test2'];
json_data.links = links_array;
I wanted to append these two string but couldn't.
Any help would be appreciate.

Assuming that the syntax of your example is correct, you can use the "push" method for arrays.
json_data = {
'name':'Testing',
'email':'TestEmail',
'links':[]
};
json_data.links.push("test1#test.com");
json_data.links.push("test2#test.com");
json_data.links.push("test3#test.com");

You have to make little changes to make it work.
First thing, You have to replace initial square brackets with curly one. By doing this your object will become JSON Literal - a key value pair.
Second thing, You have missed commas after 'name':'Testing' and 'email':'TestEmail'
Below will work perfectly:
var json_data = {
'name':'Testing',
'email':'TestEmail',
'links':[
'test#test.com',
'test#test1.com',
'test#test3.com']
}

In addition to push as mentioned by #giovannilobitos you can use concat and do it all in one go.
var json_data = {
'name':'Testing',
'email':'TestEmail',
'links':[
'test#test.com',
'test#test1.com',
'test#test3.com'
]
};
var links_array = ['testing','test2'];
json_data.links = json_data.links.concat(links_array);
console.log(json_data.links);
On MDN's array reference you can find a more complete list of how to modify arrays in JavaScript.

Parse Json result and isolate specific values

This is my returned JSON:
{
//...
"results":[
{
//more properties...
"geometry":{
"lat":51.2244644,
"lng":0.7334215
}
},
//more results...
],
//...
}
Complete JSON
I want to get information from a json result returned without having to use a specific companies JS helper file, just using the pure result myself. I'm looking to isolate results lat and lng shown here:
"geometry":{
"lat":51.2244644,
"lng":0.7334215
}
It seems like I can use code similar to this to get my result:
var json = '{"result":true,"count":1}',
obj = JSON.parse(json);
alert(obj.count);
How can I get the first coordinates returned in the result so I can later store them in an input box? I don't mind using jQuery if it simplifies this.

You can get first coordinates like following.
var json = '{"results":[{"geometry":{"lat":51.2244644,"lng":0.7334215}}]}';
var first_coordinate = JSON.parse(json).results[0].geometry;
console.log(first_coordinate);
If you want to get all coordinates in an array then try like following.
var arr = $(JSON.parse(json).results).map(function () {
return this.geometry;
}).get();
console.log(arr);

USE like this after JSON parsing
co-ordiniates from DMS
myArray.results[0].annotations.DMS
co-ordinitates from gemotery
myArray.results[0].geometry
You need to loop the results to get all co-ordinates