Converting JSON object to CSV format in JavaScript

Question

I am trying to convert a JavaScript object set in to CSV format

You can get the idea about my Javascript object, if you put it in online JSON parser https://jsonformatter.org/json-parser

This is how I tried to work it out... but it flopped.. http://jsfiddle.net/fHQzC/11/

I am trying to take the whole values corresponding to the value "term" and corresponding title in to CSV format

The expected output for is like

Time,Dec 9, 2012 
News,Germany,election, Egypt,Revolution, Japan, Earthquake
Person,Obama, Beckham
Title,Pearce Snubs Beckham                                
Time,Dec 5, Birthday
Person, Lebron James
News,Italy,Euro 2012 Final
Title-Heats National Champions

and is it possible to download the csv file in excel sheet the one I found in Stackoverflow was not really useful me...

I guess you've already checked http://stackoverflow.com/questions/4130849/convert-json-format-to-csv-format-for-ms-excel and that didn't work for you? — Ando, Jun 29 '12 at 06:33

eeqk · Answer 1 · 2021-04-07T13:06:44.970

51

Probably more elegant and the simplest solution

function convertToCSV(arr) {
  const array = [Object.keys(arr[0])].concat(arr)

  return array.map(it => {
    return Object.values(it).toString()
  }).join('\n')
}


console.log(
  convertToCSV(
    [
      {
        id: 1,
        name: 'Foo',
        timestamp: new Date()
      },
      {
        id: 2,
        name: 'Bar',
        timestamp: new Date()
      },
      {
        id: 3,
        name: 'Baz',
        timestamp: new Date()
      }
    ]
  )
)

edited Apr 07 '21 at 13:06

answered Nov 08 '19 at 15:34

eeqk

3,492
1
15
22

2

Thank you, this is exactly the solution I need. I believe this to be the best answer. – Richard Tyler Miles Mar 09 '20 at 17:52
This is exactly what I was looking for – Kirill Jul 28 '21 at 11:14
perfect solution! – ahmadalibaloch Dec 01 '21 at 19:36
2

Unfortunately this does not work if objects are improperly sorted and filled, because it assumes first object contains all fields and that their order will remain the same. – jumpjack Mar 21 '22 at 14:55
A bit shorter: ```[Object.keys(arr[0]),...arr.map(it => Object.values(it))].join('\n')``` – CennoxX Aug 03 '22 at 13:34
is this supposed to have `"data:text/csv;charset=utf-8," ` somewhere in it? – dman Jul 04 '23 at 18:31

score 30 · Answer 2 · edited Jan 03 '14 at 22:17

30

you can try as

$(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));
    });

and a function ConvertToCSV

// 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;
        }

Source

edited Jan 03 '14 at 22:17

Raghd Hamzeh

314
10
17

answered Jun 29 '12 at 06:34

Hemant Metalia

29,730
18
72
91

2

complexity does not affect this as the format of the csv will always remain same.. – Hemant Metalia Jun 29 '12 at 06:38
2

have you checked http://stackoverflow.com/questions/4130849/convert-json-format-to-csv-format-for-ms-excel ? – Hemant Metalia Jun 29 '12 at 06:39
1

Will this include a comma in a value? – Sunil Feb 22 '14 at 08:37
json is comma separated value it will not consider comma as value. you need to use some trick for that. – Hemant Metalia Feb 24 '14 at 04:29
This should be extended to be RFC4180 compliant, specifically to enclose in double quotes strings that may contain commas or line breaks, and escape any embedded double quotes. See [json2csv](https://github.com/zemirco/json2csv) – prototype Apr 22 '15 at 21:43
enclose every value in string to escape commas.. `"value", "value", "value"....\n` – Muhammad Umer Apr 02 '19 at 16:03

Eesa · Answer 3 · 2017-10-26T07:52:57.550

28

Here is my solution

function arrayToCSV(objArray) {
     const array = typeof objArray !== 'object' ? JSON.parse(objArray) : objArray;
     let str = `${Object.keys(array[0]).map(value => `"${value}"`).join(",")}` + '\r\n';

     return array.reduce((str, next) => {
         str += `${Object.values(next).map(value => `"${value}"`).join(",")}` + '\r\n';
         return str;
        }, str);
 }

Example:

let arr = [{name: "Essa", age: 25}];
console.log(arrayToCSV(arr));

edited Oct 26 '17 at 07:52

answered Oct 26 '17 at 07:32

Eesa

2,762
2
32
51

this escapes comma separated values inside columns – RisingSun Aug 27 '19 at 22:16
1

@RisingSun no it doesn't – Eesa Nov 26 '19 at 08:29

score 15 · Answer 4 · answered Nov 20 '20 at 11:52

15

Here's a solution similar to mightybruno's answer that handles strings containing commas. None of the other answers seem to take this in to consideration.

function objectsToCSV(arr) {
    const array = [Object.keys(arr[0])].concat(arr)
    return array.map(row => {
        return Object.values(row).map(value => {
            return typeof value === 'string' ? JSON.stringify(value) : value
        }).toString()
    }).join('\n')
}

answered Nov 20 '20 at 11:52

Mattijs

161
1
5

thanks very much, I also see lots of answer not taking strings containing commas into consideration. – Michael Parkadze Jun 29 '21 at 14:21

score 10 · Answer 5 · answered Nov 03 '20 at 13:14

Below code will convert and download JSON array to csv as a file.

 function exportJSONToCSV(objArray) {
    var arr = typeof objArray !== 'object' ? JSON.parse(objArray) : objArray;
    var str =
      `${Object.keys(arr[0])
        .map((value) => `"${value}"`)
        .join(',')}` + '\r\n';
    var csvContent = arr.reduce((st, next) => {
      st +=
        `${Object.values(next)
          .map((value) => `"${value}"`)
          .join(',')}` + '\r\n';
      return st;
    }, str);
    var element = document.createElement('a');
    element.href = 'data:text/csv;charset=utf-8,' + encodeURI(csvContent);
    element.target = '_blank';
    element.download = 'export.csv';
    element.click();
  }

Appreciate the code to prompt the user to download aswell. Thanks! — Ryan_DS, Apr 19 '22 at 07:56

score 2 · Answer 6 · answered May 04 '19 at 14:12

2

This is a quick & dirty, but probably works for most cases:

const headers = Object.keys(objAry[0])
console.log(headers.join())

objAry.forEach(r => console.log(
   Object.values(r)
   .map(c => Array.isArray(c)? `"${c.join()}"` : c)
   .join())
)

answered May 04 '19 at 14:12

Jeff Lowery

2,492
2
32
40

score 1 · Answer 7 · answered Jan 20 '16 at 08:55

This is my solution

https://jsfiddle.net/dhou6y3o/

function iterateObject(obj) {
  var value = '', header = '';
          for (name in obj) {
            if (obj.hasOwnProperty(name)) {
              if (isObject(obj[name])) {
                var out = iterateObject(obj[name]);
                value += out.value;
                header += out.header;
              } else {
                value += removeNewLine(obj[name]) + '; ';
                header += name + '; ';
              }
            }
          }
  return {
    "value":value,
    "header":header
  };
}
function isObject(obj) {
  return (typeof obj === 'object');
}
function removeNewLine(item) {
  return item.toString().replace(/(\r\n|\n|\r)/gm,"");
}

score 1 · Answer 8 · answered Sep 01 '20 at 19:13

1

Use papaparse library to convert JSON to CSV and Vice Versa. Refer to this link - https://www.papaparse.com/

answered Sep 01 '20 at 19:13

prakhar goyal

13
4

score 1 · Answer 9 · answered Sep 18 '20 at 00:31

Similar to mightybruno's answer but this would allow separate access to the headers and content (by moving the join statements to later in the function) if desired.

function objToCsv(data) {
    const headers = Object.keys(data[0]).join();
    const content = data.map(r => Object.values(r).join());
    return [headers].concat(content).join("\n");
}

score 0 · Answer 10 · answered Jul 06 '21 at 18:28

0

    function objToCsv(arr) {
        let claves = Object.keys(arr[0]).sort();
        let rows = claves.join(";") + "\r\n";
        arr.forEach((row) => {
          let nrow = [];
          claves.forEach((clave) => {
            let valor = JSON.stringify(row[clave]);
            nrow.push(valor.split(";").join(" ").split(",").join(" "));
          });
          rows = rows + nrow.join(";") + "\r\n";
        });
        return rows;
    }

answered Jul 06 '21 at 18:28

ronald espinoza

1

1

Welcome to StackOverflow. While this code may answer the question, providing additional context regarding *how* and/or *why* it solves the problem would improve the answer's long-term value. – Sven Eberth Jul 07 '21 at 22:17

score 0 · Answer 11 · answered Mar 21 '22 at 15:42

All the answers do not work for me, because I have a buggy object with unpredictable contents, so I had to implement my own solution which creates a "normalized" array before converting to CSV:

function objToCSV(originalArray) {
    header = [];
    result = [];
    finalCSV = "";

    originalArray.forEach(
        a => { /// Parse all rows of input ///
            row = []; // Create for each row of the input an enpty row for the output
            for (const [key, value] of Object.entries(a)) {
                /// Parse all elements of input row ///
console.log(`${key}: ${value}`);
                if (header.indexOf(`${key}`) < 0) {
                    // Add field to header if not already present
                    header.push(`${key}`);
                }
                // Put value in the right position in the array depending on field name:
                row[header.indexOf(`${key}`)]=`${value}`;
            };
            result.push(row); // Add finished line to output array
console.log("--- row separator ---");
        }
    )

    // Prepare header of CSV file:
    header.forEach(fieldName => {
        finalCSV += fieldName + "\t";
    }
    );
    finalCSV += "\n";

    // Add all rows to CSV file:
    result.forEach(row => {
        /// parse all rows of created array //
        row.forEach(col => {
            /// parse all elements of row ///
            finalCSV += col + "\t"; // Add element to output CSV row
        }
        );
        finalCSV += "\n";
    }
    );

    return finalCSV;
}

NVRM · Answer 12 · 2022-03-29T18:33:45.920

Crafted this, works fine into LibreOfice.

It does retrieve the key names to build the columns header.

let example = [
 ,,,,,
  {
    "Time": 1647672300000,
    "Open": 2937.37,
    "High": 2933.81,
    "Low": 2937.94,
    "Close": 2937.39,
    "Volume": 1547.5156
  },,,,,
]

const getCSV = (object) => {
  let csv = Object.entries(Object.entries(object)[0][1]).map((e) => e[0]).join(",");
  for (const [k,v] of Object.entries(object)) {
    csv += "\r\n" + Object.values(v).join(",") // \n is enough in linux to reduce the csv size
  }
  /* //Uncomment for file download
  let j = document.createElement("a")
  j.download = "example_"+Date.now()+".csv"
  j.href = URL.createObjectURL(new Blob([csv]))
  j.click() */
  return csv;
}

console.log(
  getCSV(example)
)

Converting JSON object to CSV format in JavaScript

12 Answers12

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