Appendix: What is JSON?

JSON (JavaScript Object Notation) is a way to store and share data in a text format that is easy for humans to read and easy for computers to understand. It looks like a list of key-value pairs (like labels and their information). How to Read It

• Curly Braces { }

  These wrap an object (a group of related information).

• Square Brackets [ ]

  These wrap a list of items (like a collection of similar things).

• Keys and Values

  Each piece of data is a pair:

  “key”: “value”

  Key = label (always in quotes)

  Value = actual information (can be text, number, true/false, another object, or a list)

Example:

{
    "name": "Alice",
    "age": 30,
    "hobbies": ["reading", "cycling"],
    "address": {
        "city": "Paris",
        "country": "France"
    }
}

Reading this out loud:

• name → “Alice”
• age → 30
• hobbies → a list of 2 things: “reading”, “cycling”
• address → another object with city and country

Even though comments are officially not a part of JSON, it is a common way to insert remarks for human readers: // comments start with a double slash and is followed by any text until the end of the line. The text is completely ignored though and has no influence on the values.

So this:

{
  "name": "Alice"
}

is equivalent to this:

{ // start of the object
  "name": "Alice" // this person's initial becomes "A"
}