Using Node.JS, how do I read a JSON file into (server) memory?

javascript json node.js
Matt Cashatt picture Matt Cashatt · Apr 4, 2012 · Viewed 561.4k times · Source

Background

I am doing some experimentation with Node.js and would like to read a JSON object, either from a text file or a .js file (which is better??) into memory so that I can access that object quickly from code. I realize that there are things like Mongo, Alfred, etc out there, but that is not what I need right now.

Question

How do I read a JSON object out of a text or js file and into server memory using JavaScript/Node?

Answer

mihai picture mihai · Apr 4, 2012

Sync:

var fs = require('fs');
var obj = JSON.parse(fs.readFileSync('file', 'utf8'));

Async:

var fs = require('fs');
var obj;
fs.readFile('file', 'utf8', function (err, data) {
  if (err) throw err;
  obj = JSON.parse(data);
});

Related questions

How to parse JSON using Node.js?

How should I parse JSON using Node.js? Is there some module which will validate and parse JSON securely?

Read More
How can I print a circular structure in a JSON-like format?

I have a big object I want to convert to JSON and send. However it has circular structure. I want to toss whatever circular references exist and send whatever can be stringified. How do I do that? Thanks. var obj = { …

Read More
Write / add data in JSON file using Node.js

I am trying to write JSON file using node from loop data, e.g.: let jsonFile = require('jsonfile'); for (i = 0; i < 11; i++) { jsonFile.writeFile('loop.json', "id :" + i + " square :" + i * i); } outPut in loop.json is: id :1 square : 1 but …

Read More