How to Open a JSON File – FAQ for New Programmers - Stringtree: Java APIs for Software Development

What is a JSON file, anyway?

JSON means JavaScript Object Notation. As the name suggests, it’s a shorthand way of noting information that is simple in comparison to other methods. JSON resembles a hybrid of a Python dictionary and a JavaScript object. Once you begin working with APIs, configs, or even data exports, you will see it everywhere.

How do I open a JSON file?

The answer depends on your definition of open. We will simplify this into a few use cases.

1. Just want to look at the file?

So long as it is of the .json variety, it can be opened with any text editors.

VS Code (recommended): Automatic JSON formatting, highlighting of different parts of code, and even auto-completion. Looking for a recommendation? This is it!
Notepad++: A more compact and faster alternative for text editing on Windows.
Basic Text Editors: Notepad, TextEdit etc (No frills but works).

How do I read JSON data in code?

In Python:

“`python

import json

with open(‘data.json’) as f:

data = json.load(f)

print(data)

`json.load()` does exactly what its name suggests It loads the content of the file into a Python dictionary or list.  

It is worth noting that `json.loads()` is meant for strings, not files.

### In JavaScript (Node.js):

javascript const fs = require(‘fs’);

const rawData = fs.readFileSync(‘data.json’);

const data = JSON.parse(rawData);

console.log(data);

fs.readFileSync() reads the file. JSON.parse() turns the raw string into an object.

`What if the JSON is malformed or huge?`

Use tools like [https://jsonlint.com](https://jsonlint.com) to validate it. If it’s massive, use a command-line tool like `jq`, or open it in chunks.

Can I write to a JSON file too?
Yes. Here’s how to save a python dictionary back in JSON:

python import json

data = { “name”: “ChatGPT”, “type”: “AI” }

with open(‘output.json’, ‘w’) as f: json.dump(data, f, indent=2) “`

Any gotchas I should watch out for?

Trailing commas is not allowed.
JSON only has advanced types, string, number, array, object, boolean, null
It doesn’t support comments. If you want comments use YAML or it’ll need to be in document notes somewhere.

TL;DR Everywhere you go, JSON is a given and can be opened through text editors without issue. The only validation one has to do is when things seem to go wrong. In code, one can read it using json.load() for Python or JSON.parse() for Java.

How to Open a JSON File – FAQ for New Programmers