# JSON Cheat Sheet

## Table of Contents

1. [Introduction to JSON](#introduction-to-json)
2. [JSON Data Types](#json-data-types)

   2.1 [String](#string)

   2.2 [Number](#number)

   2.3 [Boolean](#boolean)

   2.4 [Array](#array)

   2.5 [Object](#object)

   2.6 [Null](#null)

3. [JSON Syntax](#json-syntax)
4. [JSON Example](#json-example)
5. [Reading and Writing JSON in Python](#reading-and-writing-json-in-python)
6. [Accessing JSON Data in JavaScript](#accessing-json-data-in-javascript)
7. [Accessing JSON Data in PHP](#accessing-json-data-in-php)

```json
{
    "name": "JSON Cheet Sheet",
    "version": "1.1",
    "author": "CheetSheetz",
    "topics": ["JSON", "Data Types", "Syntax", "Example"]
}
```

## Introduction to JSON

- JSON stands for **JavaScript Object Notation**.
- It is a lightweight data interchange format.
- JSON is language-independent and easy for humans to read and write.
- Commonly used for data exchange between a server and web application, as well as for configuration files.

## JSON Data Types

### String

- Represents a sequence of characters.
- Enclosed in double quotes.
- Example: `"Hello, World!"`

### Number

- Represents a numerical value (integer or floating-point).
- Example: `42` or `3.14`

### Boolean

- Represents a logical value, either `true` or `false`.

### Array

- Ordered list of values.
- Enclosed in square brackets `[]`.
- Example: `[1, 2, "three", true]`

### Object

- Unordered collection of key-value pairs.
- Enclosed in curly braces `{}`.
- Example: `{"name": "John", "age": 30, "city": "New York"}`

### Null

- Represents a null or empty value.

## JSON Syntax

- Data is represented in key-value pairs.
- Keys are always strings and followed by a colon.
- Pairs are separated by commas.
- Objects are enclosed in curly braces `{}`.
- Arrays are enclosed in square brackets `[]`.

## JSON Example

```json
{
    "name": "John Doe",
    "age": 25,
    "isStudent": false,
    "courses": ["Math", "History", "Science"],
    "address": {
        "street": "123 Main St",
        "city": "Anytown",
        "zip": "12345"
    },
    "contact": null
}
```

## 5. Reading and Writing JSON in Python

```python
import json

# Reading JSON from a file
with open('data.json', 'r') as json_file:
    data = json.load(json_file)
    print(data)

# Writing Python data to a JSON file
data_to_write = {"name": "Jane Doe", "age": 30, "city": "AnotherTown"}

with open('output.json', 'w') as json_file:
    json.dump(data_to_write, json_file, indent=4)
```

## Accessing JSON Data in JavaScript

```javascript
// Assuming jsonString is a JSON string
var jsonData = JSON.parse(jsonString);

// Accessing data
console.log(jsonData.name); // Outputs: John Doe
console.log(jsonData.address.city); // Outputs: Anytown
```

## Accessing JSON Data in PHP

```php
// Assuming jsonString is a JSON string
$jsonData = json_decode($jsonString, true);

// Accessing data
echo $jsonData['name']; // Outputs: John Doe
echo $jsonData['address']['city']; // Outputs: Anytown
```