JSON Object Literals

This is a JSON string:

'{"name":"John", "age":30, "car":null}'

Inside the JSON string there is a JSON object literal:

{"name":"John""age":30"car":null}

JSON object literals are surrounded by curly braces {}.

JSON object literals contains key/value pairs.

Keys and values are separated by a colon.

Keys must be strings, and values must be a valid JSON data type:

  a string

  a number

  an object

  an array

  a boolean

  null

Each key/value pair is separated by a comma.


JavaScript Objects

You can create a JavaScript object from a JSON object literal:

myObj = {"name":"John""age":30"car":null};

EXAMPLE ❯


Accessing Object Values

You can access object values by using dot (.) notation:

Example:

const myJSON = '{"name":"John", "age":30, "car":null}';
const myObj = JSON.parse(myJSON);
x = myObj.name;

You can also access object values by using bracket ([]) notation:

EXAMPLE ❯


Looping an Object

You can loop through object properties with a for-in loop:

Example:

const myJSON = '{"name":"John", "age":30, "car":null}';
const myObj = JSON.parse(myJSON);

let text = "";
for (const x in myObj) {
  text += x + ", ";
}

In a for-in loop, use the bracket notation to access the property values:

EXAMPLE ❯