Why use [] around object literals

Thanks.

andren I see two JSON, one is

[
  {
   "name": "Aimee",
   "inoffice": false
  },

and other

{
    "jobs": [
        {
            "id": 7,
            "title": "Software engineer",
            "employer": {
                "name": "IBM"
            },
            "location": "Manchester",
            "salary": "£45,000+"
        },
    ],
}

Is accessing them the same?

In the first example you have an object inside of an array, in the second example you have an object which has a property (jobs) which stores an array, which itself stores an object, and that object has a property (employer) which also stores an object. It is a good example of how you can nest arrays and objects freely to create pretty complex structures in JavaScript and JSON .

As far as accessing it, you access them the same way you would access an array or an object in JavaScript normally. That is by using bracket notation with an index to pull out items from arrays, and using either dot notation or bracket notation to pull property values out of objects. I can demonstrate it by giving some code examples, for all of these examples I'm assuming the JSON has been stored in a variable called json.

Let's say I wanted to access the name property in your first example, the code would look like this:

// Pull out the first item from the array using its index (that results in an object)
// then pull out the name property from that object using dot syntax (that results in a string)
json[0].name

Let's say I wanted to access the title property in your second example that would look like this:

// Pull out the jobs property from the object using dot notation (that results in an array)
// then pull out the first item from that array using its index (that results in an object)
// then pull out the title property from that item using dot notation (that results in a string)
json.jobs[0].title

Let's say I wanted to access the name property in your second example that would look like this:

// Pull out the jobs property from the object using dot notation (that results in an array)
// then pull out the first item from that array using its index (that results in an object)
// then pull out the employer property from that object using dot notation (that results in another object)
// then pull out the name property from that object using dot notation (that results in a string)
json.jobs[0].employer.name

As you can see once you start nesting multiple arrays and objects inside of each other you end up making it more complicated to access them. It can be hard to wrap your mind around in the beginning, but once you have spend some time working with JSON it starts to become easier to conceptualize how it is structured and how you can access the various properties.