Javascript: How to convert an JSON arrays in array into an CSV file?

Question

I'm struggeling with my JSON file here... This is what I get from my processing .php-file as a response:

{"1":{"Nachname":"Stromberg","Vorname":"Bernd", 
"Benutzername":"strombergbernd12","Password":"Xrz5Bv6A"},
"2":{"Nachname":"Heisterkamp","Vorname":"Ernie", 
"Benutzername":"heisterkampernie12","Password":"aOq24EpF"}}

Now, I want to build from this JSON array a csv file. In the first row the csv file should mention the headers Nachname, Vorname, Benutzername and Password and then list in the following rows the rest of the data.

I cant handle that, can you help me?

• user3483203: What do you mean, "I can't handle that"? What have you tried?
• Dawko: well, I tried different codes of converting arrays and json's to csv files, but all I get is junk or nothing in the csv in the end.
• Jeremy Thille: You start from a JSON. CSV are Comma Separated Values. Therefore, you need to transform your data before exporting it to CSV. What's the expected output?
• Eddie: You need to include the different codes you've tried on your post.
• user3483203: Here is a hint, to get the headers for your csv, you can use Object.keys()

Answer 1

once you have your json as text you parse it:

var json = JSON.parse(jsonAsText);

transform it to an array:

json = Object.values(json);

init your result:

var csv = "";

keep header keys somewhere:

var keys = (json[0] && Object.keys(json[0])) || [];

write header row

csv += keys.join(',') + '\n';

iterate and put everything in csv

for (var line of json) {
 csv += keys.map(key => line[key]).join(',') + '\n';
}

Your csv content should be ready

var json = {
 "1": {
 "Nachname": "Stromberg",
 "Vorname": "Bernd",
 "Benutzername": "strombergbernd12",
 "Password": "Xrz5Bv6A"
 },
 "2": {
 "Nachname": "Heisterkamp",
 "Vorname": "Ernie",
 "Benutzername": "heisterkampernie12",
 "Password": "aOq24EpF"
 }
}
function toCSV(json) {
 json = Object.values(json);
 var csv = "";
 var keys = (json[0] && Object.keys(json[0])) || [];
 csv += keys.join(',') + '\n';
 for (var line of json) {
 csv += keys.map(key => line[key]).join(',') + '\n';
 }
 return csv;
}
console.log(toCSV(json));

---

Note: If you can, switch your json to Array syntax:

[
 {
 "Nachname":"Stromberg",
 "Vorname":"Bernd",
 "Benutzername":"strombergbernd12",
 "Password":"Xrz5Bv6A"
 },
 {
 "Nachname":"Heisterkamp",
 "Vorname":"Ernie", 
 "Benutzername":"heisterkampernie12",
 "Password":"aOq24EpF"
 }
]

and then remove this line:

json = Object.values(json);

• Dawko: wow, you're a genius! I'm not used to json & javascript at all. Sorry for my dumb question - must have been pretty obvious to you. Thank you so much!
• Apolo: Note that json = Object.values(json); is a waste of ressource. If you can you should use the array syntax in your json (["item1", "item2", ...]) and remove this line
• Dawko: $header = array('Nachname', 'Vorname'); $results[$number] += array_combine($header, array($usernachname, $uservorname)); $results[$number] += array_combine($header, array($postuname, $pass)); How can I build your kind of Array? I dont get how to build it, and without the indexes, how can I call one specific item? Wait, actually I dont need to call one specific item...
• Dawko: Got it through a second array: $user = array(); $user += ['Nachname' => $usernachname]; $user += ['Vorname' => $uservorname]; $user += ['Benutzername' => $postuname]; $user += ['Password' => $pass]; $results[] = $user;
• Dawko: Had to replace your "for(var line of json)" to make it IE11 compatible. Danny's code helped me: for (var item in json) { csv += Object.values(json[item]).join(","); csv += "\n"; }

Answer 2

You could use: Object.keys() and Object.values().

Something like this:

(function() {
 var data = {
 "1": {
 "Nachname": "Stromberg",
 "Vorname": "Bernd",
 "Benutzername": "strombergbernd12",
 "Password": "Xrz5Bv6A"
 },
 "2": {
 "Nachname": "Heisterkamp",
 "Vorname": "Ernie",
 "Benutzername": "heisterkampernie12",
 "Password": "aOq24EpF"
 }
 };
 var csv = Object.keys(data[Object.keys(data)[0]]).join(","); // Header columns.
 csv += "\n";
 for (var item in data) {
 csv += Object.values(data[item]).join(",");
 csv += "\n";
 }
 console.log(csv);
}());

.as-console-wrapper {
 position: relative;
 top: 0;
}

The result will be:

enter image description here

• Apolo: data[1] will fail with a single item ;)
• Danny Fardy Jhonston Bermúdez: @Apolo Fixed it. Thank you for the observation.
• Dawko: @DannyFardyJhonstonBermúdez took your for (var item in json) line to make it IE11 compatible - thank you!