JSON

JSON is a simple yet very useful way of storing data. It's a plain-text file with some structured data inside.

There are six types in JSON: number (integer/float), object, array, boolean, null, and string.

  • Object ✨. An object is wrapped inside {}. It's a structure with keys that are associated with a value.
{
  "key": 1,
  "key2": "string",
  "key3": false,
  "key4": { "key1": "string" },
  "key5": [],
  "key6": null
}
  • Array 🤓: simply an array of values
[
    42,
    "string", 
    true,
    null,
    { "key1": "value" },
    []
]
  • Example 🎁: a list (array) of users (objects) 
[
    { "username": "toto", "password": "toto" },
    { "username": "tata", "password": "tata" },
    { "username": "titi", "password": "titi" }
]

Extensions

JSON5

Some are not satisfied with the limited syntax of JSON. Here are some limitations:

  • ✏️ You can't use comments (// comment) in JSON
  • 🎡 There are no multiline strings, so it's not easy to read/write long strings in JSON. A good editor would have a feature to wrap the JSON, to avoid very long lines
  • ...

So, they created JSON5. It's not quite used widely.

GeoJSON

"GeoJSON is a format for encoding a variety of geographic data structures".