How do I add to an existing json file in node.js

Question

I am new to Node.js and JavaScript. I have a results.json file that I want to keep a running log of results from a script that pulls images from the web. However, my current script only overwrites the existing result. How do I build upon or add to the results.json so each subsequent result is logged in the results.json file? I would like it to be valid json.

Here is general example:

var currentSearchResult = someWebSearchResult var fs = require('fs'); var json = JSON.stringify(['search result: ' + currentSearchResult + ': ', null, "\t"); fs.writeFile("results.json", json); 

And the results.json:

[     "search result: currentSearchResult" ] 

Answer 1

If you want the file to be valid JSON, you have to open your file, parse the JSON, append your new result to the array, transform it back into a string and save it again.

var fs = require('fs')  var currentSearchResult = 'example'  fs.readFile('results.json', function (err, data) {     var json = JSON.parse(data)     json.push('search result: ' + currentSearchResult)      fs.writeFile("results.json", JSON.stringify(json)) })