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

Question

I have a link that opens up JSON data in the browser, but unfortunately I have no clue how to read it. Is there a way to convert this data using JavaScript in CSV format and

Answer 1

I wanted to riff off @Christian Landgren's answer above. I was confused why my CSV file only had 3 columns/headers. This was because the first element in my json only had 3 keys. So you need to be careful with the const header = Object.keys(json[0]) line. It's assuming that the first element in the array is representative. I had messy JSON that with some objects having more or less.

So I added an array.sort to this which will order the JSON by number of keys. So that way your CSV file will have the max number of columns.

This is also a function that you can use in your code. Just feed it JSON!

function convertJSONtocsv(json) {
    if (json.length === 0) {
        return;
    }

    json.sort(function(a,b){ 
       return Object.keys(b).length - Object.keys(a).length;
    });

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

    fs.writeFileSync('awesome.csv', csv)
}