How To Parse JSON in Node.js

Written by Rahul, Updated on August 17, 2019

Introduction

This tutorial will help you to read JSON file using Node.js. This tutorial uses readFile and readFileSync functions of the jsonfile module.

Requirements

The first requirement is to have node.js and npm installed on your system. If not already installed use below links.

For this tutorial, we are using jsonfile npm module. So first you need to install jsonfile module on your system

npm install jsonfile --save

Now, I am creating a dummy json file employee.json. You can use your own json file.
Filename: employee.json

[
  {
    "emp_id" : "101",
    "emp_name" : "Mike",
    "emp_addr" : "123 California, USA",
    "designation" : "Editor"
  },
  {
    "emp_id" : "102",
    "emp_name" : "Jacob",
    "emp_addr" : "456 Log Angelis, USA",
    "designation" : "Chief Editor"
  }
]

Read JSON File with Nodejs – Option #1

In the above step, I have created a sample JSON file. Now create ReadJsonFile.js and add following content. You need to change employee.json with your JSON file name.

Filename: ReadJsonFile.js

var jsonFile = require('jsonfile')
var fileName = 'employee.json'

jsonFile.readFile(fileName, function(err, jsonData) {
  if (err) throw err;
  for (var i = 0; i < jsonData.length; ++i) {

    console.log("Emp ID: "+jsonData[i].emp_id);
    console.log("Emp Name: "+jsonData[i].emp_name);
    console.log("Emp Address: "+jsonData[i].emp_addr);
    console.log("Designation: "+jsonData[i].designation);
    console.log("----------------------------------");
  }
});

var jsonFile = require('jsonfile')

var fileName = 'employee.json'

jsonFile.readFile(fileName, function(err, jsonData) {

if (err) throw err;

for (var i = 0; i < jsonData.length; ++i) {

console.log("Emp ID: "+jsonData[i].emp_id);

console.log("Emp Name: "+jsonData[i].emp_name);

console.log("Emp Address: "+jsonData[i].emp_addr);

console.log("Designation: "+jsonData[i].designation);

console.log("----------------------------------");

}

});

Now run the nodejs script using following command.

node ReadJsonFile.js 

Emp ID: 101
Emp Name: Mike
Emp Address: 123 California, USA
Designation: Editor
----------------------------------
Emp ID: 102
Emp Name: Jacob
Emp Address: 456 Log Angelis, USA
Designation: Chief Editor
----------------------------------

Read JSON File with Nodejs – Option #2

Alternatively, you can use readFileSync function to read json file content. Create a ReadJsonFileSync.js file with following content. You can read here about the differences of readFile and readFileSync function in Jode.js.

Filename: ReadJsonFileSync.js

var jsonFile = require('jsonfile')
var fileName = 'employee.json'

var jsonData = jsonFile.readFileSync(fileName);

for (var i = 0; i < jsonData.length; ++i) {

	console.log("Emp ID : "+jsonData[i].emp_id);
	console.log("Emp Name : "+jsonData[i].emp_name);
	console.log("Emp Address : "+jsonData[i].emp_addr);
	console.log("Designation : "+jsonData[i].designation);
	console.log("----------------------------------");
}

var jsonFile = require('jsonfile')

var fileName = 'employee.json'

var jsonData = jsonFile.readFileSync(fileName);

for (var i = 0; i < jsonData.length; ++i) {

console.log("Emp ID : "+jsonData[i].emp_id);

console.log("Emp Name : "+jsonData[i].emp_name);

console.log("Emp Address : "+jsonData[i].emp_addr);

console.log("Designation : "+jsonData[i].designation);