How to convert JSON to CSV format and store in a variable

Very nice solution by praneybehl, but if someone wants to save the data as a csv file and using a blob method then they can refer this:

function JSONToCSVConvertor(JSONData, ReportTitle, ShowLabel) {

    //If JSONData is not an object then JSON.parse will parse the JSON string in an Object
    var arrData = typeof JSONData != 'object' ? JSON.parse(JSONData) : JSONData;
    var CSV = '';
    //This condition will generate the Label/Header
    if (ShowLabel) {
        var row = "";

        //This loop will extract the label from 1st index of on array
        for (var index in arrData[0]) {
            //Now convert each value to string and comma-seprated
            row += index + ',';
        }
        row = row.slice(0, -1);
        //append Label row with line break
        CSV += row + '\r\n';
    }

    //1st loop is to extract each row
    for (var i = 0; i < arrData.length; i++) {
        var row = "";
        //2nd loop will extract each column and convert it in string comma-seprated
        for (var index in arrData[i]) {
            row += '"' + arrData[i][index] + '",';
        }
        row.slice(0, row.length - 1);
        //add a line break after each row
        CSV += row + '\r\n';
    }

    if (CSV == '') {
        alert("Invalid data");
        return;
    }

    //this trick will generate a temp "a" tag
    var link = document.createElement("a");
    link.id = "lnkDwnldLnk";

    //this part will append the anchor tag and remove it after automatic click
    document.body.appendChild(link);

    var csv = CSV;
    blob = new Blob([csv], { type: 'text/csv' });
    var csvUrl = window.webkitURL.createObjectURL(blob);
    var filename =  (ReportTitle || 'UserExport') + '.csv';
    $("#lnkDwnldLnk")
        .attr({
            'download': filename,
            'href': csvUrl
        });

    $('#lnkDwnldLnk')[0].click();
    document.body.removeChild(link);
}

Ok I finally got this code working:

<html>
<head>
    <title>Demo - Covnert JSON to CSV</title>
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
    <script type="text/javascript" src="https://github.com/douglascrockford/JSON-js/raw/master/json2.js"></script>

    <script type="text/javascript">
        // JSON to CSV Converter
        function ConvertToCSV(objArray) {
            var array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;
            var str = '';

            for (var i = 0; i < array.length; i++) {
                var line = '';
                for (var index in array[i]) {
                    if (line != '') line += ','

                    line += array[i][index];
                }

                str += line + '\r\n';
            }

            return str;
        }

        // Example
        $(document).ready(function () {

            // Create Object
            var items = [
                  { name: "Item 1", color: "Green", size: "X-Large" },
                  { name: "Item 2", color: "Green", size: "X-Large" },
                  { name: "Item 3", color: "Green", size: "X-Large" }];

            // Convert Object to JSON
            var jsonObject = JSON.stringify(items);

            // Display JSON
            $('#json').text(jsonObject);

            // Convert JSON to CSV & Display CSV
            $('#csv').text(ConvertToCSV(jsonObject));
        });
    </script>
</head>
<body>
    <h1>
        JSON</h1>
    <pre id="json"></pre>
    <h1>
        CSV</h1>
    <pre id="csv"></pre>
</body>
</html>

Thanks alot for all the support to all the contributors.

Praney


A more elegant way to convert json to csv is to use the map function without any framework:

var json = json3.items
var fields = Object.keys(json[0])
var replacer = function(key, value) { return value === null ? '' : value } 
var csv = json.map(function(row){
  return fields.map(function(fieldName){
    return JSON.stringify(row[fieldName], replacer)
  }).join(',')
})
csv.unshift(fields.join(',')) // add header column
 csv = csv.join('\r\n');
console.log(csv)

Output:

title,description,link,timestamp,image,embed,language,user,user_image,user_link,user_id,geo,source,favicon,type,domain,id
"Apple iPhone 4S Sale Cancelled in Beijing Amid Chaos (Design You Trust)","Advertise here with BSA Apple cancelled its scheduled sale of iPhone 4S in one of its stores in China’s capital Beijing on January 13. Crowds outside the store in the Sanlitun district were waiting on queues overnight. There were incidents of scuffle between shoppers and the store’s security staff when shoppers, hundreds of them, were told that the sales [...]Source : Design You TrustExplore : iPhone, iPhone 4, Phone","http://wik.io/info/US/309201303","1326439500","","","","","","","","","wikio","http://wikio.com/favicon.ico","blogs","wik.io","2388575404943858468"
"Apple to halt sales of iPhone 4S in China (Fame Dubai Blog)","SHANGHAI – Apple Inc said on Friday it will stop selling its latest iPhone in its retail stores in Beijing and Shanghai to ensure the safety of its customers and employees. Go to SourceSource : Fame Dubai BlogExplore : iPhone, iPhone 4, Phone","http://wik.io/info/US/309198933","1326439320","","","","","","","","","wikio","http://wikio.com/favicon.ico","blogs","wik.io","16209851193593872066"

Update ES6 (2016)

Use this less dense syntax and also JSON.stringify to add quotes to strings while keeping numbers unquoted:

const items = json3.items
const replacer = (key, value) => value === null ? '' : value // specify how you want to handle null values here
const header = Object.keys(items[0])
const csv = [
  header.join(','), // header row first
  ...items.map(row => header.map(fieldName => JSON.stringify(row[fieldName], replacer)).join(','))
].join('\r\n')

console.log(csv)

Tags:

Javascript

Csv

Json

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