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);
JSON:
[{"CDATE":"0000-00-00","DISTANCE":"0"},
{"CDATE":"0000-00-00","DISTANCE":"1"},
{"CDATE":"0000-00-00","DISTANCE":"2"},
{"CDATE":"0000-00-00","DISTANCE":"3"}]
Is it possible to put all the distance value in their own array in JS? The formatting will be consistent as it comes from an API and is always formatted correctly.
What I've tried:
var arry = [ /* JSON noted above */ ];
alert(arry[1])
and
var arry = JSON.parse([ /* JSON noted above */ ]);
alert(arry[1])
Expected:
1
Actual:
{"CDATE":"0000-00-00","DISTANCE":"1"}
and the other gives an error.
I would like to extract just the DISTANCE value as an array of DISTANCE
I've tried JSON.parse() but I don't think this is what I am after as it hasn't worked for me.
Use .map
var data = [{"CDATE":"0000-00-00","DISTANCE":"0"},
{"CDATE":"0000-00-00","DISTANCE":"1"},
{"CDATE":"0000-00-00","DISTANCE":"2"},
{"CDATE":"0000-00-00","DISTANCE":"3"}];
var distance = data.map(el => el.DISTANCE);
console.log(distance[2]);
console.log(distance);
It is already a valid json so you do not need to use JSON.parse()
Currently I need the URL for an image and I am getting it through the JSON file. I am not sure to acquire the key that has the URL due to the key having a # at the start. Here is the JSON:
{
"#text":"https://lastfm-img2.akamaized.net/i/u/34s/3ed37777196a6f2c29c02a1a58a93e4d.png",
"size":"small"
},
{
"#text":"https://lastfm-img2.akamaized.net/i/u/64s/3ed37777196a6f2c29c02a1a58a93e4d.png",
"size":"medium"
}
Same as with every other time you encounter some JSON string!
The # is an invalid character in a property name, work around is the bracket notation: «object»[property] --> «array»[index]['#text'].
We can use forEach to extract the results.
var string = '[{"#text":"https://lastfm-img2.akamaized.net/i/u/34s/3ed37777196a6f2c29c02a1a58a93e4d.png","size":"small"},{"#text":"https://lastfm-img2.akamaized.net/i/u/64s/3ed37777196a6f2c29c02a1a58a93e4d.png","size":"medium"}]';
var parsed = JSON.parse(string);
//parsed is an array, we can loop over it
parsed.forEach(function(obj) {
console.log(obj['#text']);
});
Even prettier would be if you can select from the array based on size:
var string = '[{"#text":"https://lastfm-img2.akamaized.net/i/u/34s/3ed37777196a6f2c29c02a1a58a93e4d.png","size":"small"},{"#text":"https://lastfm-img2.akamaized.net/i/u/64s/3ed37777196a6f2c29c02a1a58a93e4d.png","size":"medium"}]';
function getImageUrlBySize(size, json) {
var parsed = JSON.parse(json);
return parsed.find(function(element) { //modern browsers only (no IE)
return element['size'] == size;
})['#text']; //add text here since find returns the full item
}
console.log(getImageUrlBySize('small', string));
I try get the sessionid before REST function, but in the case if I does not convert toString(); show only numbers (21 22 2e ...).
See this image:
1º:
Obs.: Before using split.
!!xxxxxxx.xxxxx.xxxxxxx.rest.schema.xxxxResp {error: null, sessionID: qdaxxxxxxxxxxxxxj}
My code:
var Client = require('./lib/node-rest-client').Client;
var client = new Client();
var dataLogin = {
data: { "userName":"xxxxxxxx","password":"xxxxxxxx","platform":"xxxxx" },
headers: { "Content-Type": "application/json" }
};
client.registerMethod("postMethod", "xxxxxxxxxxx/login", "POST");
client.methods.postMethod(dataLogin, function (data, response) {
// parsed response body as js object
// console.log(data); all return, image 1
// raw response
if(Buffer.isBuffer(data)){
data = data.toString('utf8'); // if i does not convert to string, return numbers, see image 1..
console.log(data); //all inside image 2, and i want just value from sessionid
var output = data;
var res = output.split(" "); // using split
res = res[4].split("}", 1);
}
console.log(res); //image 3
});
I tested with JSON.parse and JSON.stringify and it did not work, show just 'undefined' for all. After convert toString();, And since I've turned the values into string, I thought of using split to get only the value of sessionid.
And when I used split, all transform to array and the return is from console.log(data), see image 2:
2º:
Obs.: After use split and convert to array automatically.
And the return after use split is with the conditions inside my code:
3º:
And the return after use split is with the conditions inside my code:
[ 'bkkRQxxxxxxxxxxxxx' ]
And I want just:
bkkRQxxxxxxxxxxxxx
I would like to know how to solve this after all these temptations, but if you have another way of getting the sessionid, I'd be happy to know.
Thanks advance!
After converting the Buffer to a string, remove anything attached to the front with using data.substr(data.indexOf('{')), then JSON.parse() the rest. Then you can just use the object to get the sessionID.
if(Buffer.isBuffer(data)){
data = data.toString('utf8');
data = data.substr(data.indexOf('{'));
obj = JSON.parse(data);
console.log(obj.sessionID);
}
EDIT:
The issue you are having with JSON.parse() is because what is being returned is not actually JSON. The JSON spec requires the properties to be quoted ("). See this article
If the string looked like this, it would work: {"error": null, "sessionID": qdaxxxxxxxxxxxxxj}
Because the json is not really json, you can use a regular expression to get the info you want. This should get it for you.
re = /(sessionID: )([^,}]*)/g;
match = re.exec(data);
console.log(match[2]);
EDIT 2: After fully reading the article that I linked above (oops haha), this is a more preferable way to deal with unquoted JSON.
var crappyJSON = '{ somePropertyWithoutQuotes: "theValue!" }';
var fixedJSON = crappyJSON.replace(/(['"])?([a-zA-Z0-9_]+)(['"])?:/g, '"$2": ');
var aNiceObject = JSON.parse(fixedJSON);
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.