How To Parse JSON in Node.js

JSON, or JavaScript Object Notation, is a lightweight data-interchange format that is easy for humans to read and write. Node.js has built-in support for parsing JSON files, making it a breeze to work with JSON data. To parse a JSON file in Node.js, you can use the built-in JSON module. The JSON module provides an efficient way to parse and stringify JSON data. It also provides a number of helpful methods for working with JSON data.

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

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Installing Node Module

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

npm install jsonfile --save 

Next create a sample json file for running few examples. You can use your own json file.

nano employee.json 

Add the follwoing snippte:

[
  {
    "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"
  }
]

Save file content and close it.

Next, we will run a few examples to read JSON file created above.

Option #1: Read JSON File with Nodejs

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

Filename: ReadJsonFile.js

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
----------------------------------

Option #2: Read JSON File (readFileSync)

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

Now run the nodejs script using following command.

node ReadJsonFileSync.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
----------------------------------