JavaScript and JSON

the preferred data format of the internet

JSON (JavaScript Object Notation) allows for storing small sets of data in a relatively simple but robust structure:

The basic structure of a JSON object

The simplest JSON object looks like:

{ "property" : "value" }

In a browser console, let us take the basic JSON object above and assign it a variable called jsonObject:

> let jsonObject = { "property" : "value" };
<- undefined

It responds with "undefined" but let us enter the following again into the console to confirm that the object exists:

> jsonObject 
<- {property: "value"}

Notations for the notations

We could then use the dot notation object.property:

> jsonObject.property
<- "value"

Or, we could use the associative array notation object["property"]:

> jsonObject["property"]
<- "value"

The associative array notation becomes useful when the property names lengthen so much that we would need to use "kebab-notation", the stringing of multiple words with dashes!

let obj = { "example-of-a-very-long-property-name" : "its value" }

We would then access that property like such:

> obj["example-of-a-very-long-property-name"]

Objects with more than one property

Naturally, an object could have multiple property-value pairs:

{ 
  "property1" : "value1", 
  "property2" : "value2", 
  "property3" : "value3", 
  ... 
} 

Calling the above jsonObject, we would enter jsonObject.property2 or jsonObject["property2"] into a console to yield "value2"

> jsonObject["property2"]
<- "value2"

Objects inside of objects

The object could also have properties with values that themselves have sub-objects:

{ 
  "property1" : { 
    "property1A" : "value1A" 
  }, 
  "property2" : { 
    "property2A" : "value2A", 
    "property2B" : "value2B" 
  }, 
  "property3" : "value3" 
}

Calling the above jsonObject, we would enter jsonObject.property2.property2B or jsonObject["property2"]["property2B"] (a two-dimensional array) into a console to yield "value2B")

> jsonObject["property2"]["property2B"]
<- "value2B"

We can then infer here that this versatile structure could allow for quite complex objects with many properties and sub-properties to the desired degree!