How to access array of objects in JavaScript code example

Example 1: list javascript

//Creating a list
var fruits = ["Apple", "Banana", "Cherry"];

//Creating an empty list
var books = [];

//Getting element of list
//Lists are ordered using indexes
//The first element in an list has an index of 0, 
//the second an index of 1,
//the third an index of 2,
//and so on.
console.log(fruits[0]) //This prints the first element 
//in the list fruits, which in this case is "Apple"

//Adding to lists
fruits.push("Orange") //This will add orange to the end of the list "fruits"
fruits[1]="Blueberry" //The second element will be changed to Blueberry

//Removing from lists
fruits.splice(0, 1) //This will remove the first element,
//in this case Apple, from the list
fruits.splice(0, 2) //Will remove first and second element
//Splice goes from index of first argument to index of second argument (excluding second argument)

Example 2: javascript array

//create an array like so:
var colors = ["red","blue","green"];

//you can loop through an array like this:
for (var i = 0; i < colors.length; i++) {
    console.log(colors[i]);
}

Example 3: array of objects javascript

var widgetTemplats = [
    {
        name: 'compass',
        LocX: 35,
        LocY: 312
    },
    {
        name: 'another',
        LocX: 52,
        LocY: 32
    }
]

Example 4: create array of objects javascript

let products = [
  {
    name: "chair",
    inventory: 5,
    unit_price: 45.99
  },
  {
    name: "table",
    inventory: 10,
    unit_price: 123.75
  },
  {
    name: "sofa",
    inventory: 2,
    unit_price: 399.50
  }
];
function listProducts(prods) {
  let product_names = [];
  for (let i=0; i<prods.length; i+=1) {
   product_names.push(prods[i].name);
  }
  return product_names;
}
console.log(listProducts(products));
function totalValue(prods) {
  let inventory_value = 0;
  for (let i=0; i<prods.length; i+=1) {
    inventory_value += prods[i].inventory * prods[i].unit_price;
  }
  return inventory_value;
}
console.log(totalValue(products));

Example 5: javascript array read object value in array

var events = [
  {
    userId: 1,
    place: "Wormholes Allow Information to Escape Black Holes",
    name: "Check out this recent discovery about workholes",
    date: "2020-06-26T17:58:57.776Z",
    id: 1
  },
  {
    userId: 1,
    place: "Wormholes Allow Information to Escape Black Holes",
    name: "Check out this recent discovery about workholes",
    date: "2020-06-26T17:58:57.776Z",
    id: 2
  },
  {
    userId: 1,
    place: "Wormholes Allow Information to Escape Black Holes",
    name: "Check out this recent discovery about workholes",
    date: "2020-06-26T17:58:57.776Z",
    id: 3
  }
];
console.log(events[0].place);

Example 6: how to access array of objects in javascript

Accessing nested data structures
A nested data structure is an array or object which refers to other arrays or objects, i.e. its values are arrays or objects. Such structures can be accessed by consecutively applying dot or bracket notation.

Here is an example:

const data = {
    code: 42,
    items: [{
        id: 1,
        name: 'foo'
    }, {
        id: 2,
        name: 'bar'
    }]
};
Let's assume we want to access the name of the second item.

Here is how we can do it step-by-step:

As we can see data is an object, hence we can access its properties using dot notation. The items property is accessed as follows:

data.items
The value is an array, to access its second element, we have to use bracket notation:

data.items[1]
This value is an object and we use dot notation again to access the name property. So we eventually get:

const item_name = data.items[1].name;
Alternatively, we could have used bracket notation for any of the properties, especially if the name contained characters that would have made it invalid for dot notation usage:

const item_name = data['items'][1]['name'];