Posted in javascript
9026
2:37 am, March 28, 2022
 

Javascript Objects Notes

As javascript objects are used so often in javascript i thought i would write an overview and some notes on how they work, well how they work for me anyway. I guess how they work for me should be similar to how they just work, so should be good. 

What is a Javascript Object?

  1. A javscript object is a collection of named values.
  2. Objects is an unordered collection of key value pairs.
  3. Javascript Objects are like an array, but not actually an array.  

An example of a Javascript Object

Javascript

const my_object = {
    "my_object_1": "value1",
    "my_object_2": "value2",
    "my_object_3": "value3"
}

Accessing Properties of an Object

Lets take the my_object and access value2 from it. 

You can do this with : objectName.property

or like this

objectName["property"]

Javascript

console.log(my_object.my_object_2);

Convert an Object to An Array

You can convert your javascript object into an array with Object.values(objectName);

Javascript

/* an array of the object called my_object_array */
const my_object_array = Object.values(my_object);
console.log(my_object_array);

Loop throught the new array

Usually i forget how to do this, so i thought i would add it here to see if it jogs my memory. 

The array is now called my_object_array

This seems to work:

Javascript

/* foreach on the array function */
let out = "";
my_object_array.forEach(do_stuff_function);
function do_stuff_function(value, index, array) {
  out += "value: " + value + ", index: " + index + "array: " + array;
}
console.log(out);

Object Methods

You can add things like functions inside objects, which makes them even more useful than arrays. 

add code and example... 

Constructor

A blue print for creating objects. 

 

Javascript

const my_object = {
    "my_object_1": "value1",
    "my_object_2": "value2",
    "my_object_3": "value3"
}
console.table(my_object);

// console.log the value of my_object.my_object_2
console.log(my_object.my_object_2);

// console.log the value of objectName["property"]
console.log( my_object["my_object_2"] );

// an array of the object called my_object_array
const my_object_array = Object.values(my_object);
console.log(my_object_array);

// foreach on the array function
let out = "";
my_object_array.forEach(do_stuff_function);
function do_stuff_function(value, index, array) {
  out += "value: " + value + ", index: " + index + "array: " + array;
}
console.log(out);

View Statistics
This Week
218
This Month
1003
This Year
2866

No Items Found.

Add Comment
Type in a Nick Name here
 
Other Items in javascript
get current year in javascript find a text string and replace it in javascript check if an item id exists in javascript Twitter Post Fetcher v18.0.4 - javascript twitter feed fetcher Are you sure you want to navigate away from this page? #JavaScript warning floating message box on bottom right of screen with close button share to twitter javascript button function open a new window share to linked in current url button with javascript Get current URL and add a share to facebook share button with it encode url with javascript Twitter Post Fetcher Script Javascript Objects Notes javascript add class to element update value of element using javascript javascript attach a click event to an id not using jquery console dir usage how to write a javascript string over multiple lines best way to write html into an existing page javascript Uncaught TypeError: Cannot set properties of null (setting 'onclick') check url hash using javascript submit form with javascript Converting PHP to Javascript for State Extraction by numeric value Australian State Names get the value from a textarea element javascript get content from element convert characters to entities using javascript replace Auto Create HTML Code Snippets loop to arr.length or array length get tomorrows date with javascript get yesterdays date with javascript add new random image with button Create Strings using Template Literals Darkmode JS - Add darkmode to your site with one script Use destructuring assignment within the argument to the function half to send only max and min inside the function. Using Destructuring and the Rest Parameter to Reassign Array Elements Use destructuring assignment to swap the values of a and b Sweet Alert 2 Methods and Examples How to Assign the Value of One Variable to Another in Javascript Slick Slider Carousel with Custom Next and Prev Buttons Console Tips and Tricks javascript random string to put on url for cache javascript try catch example function load json data url or api with javascript log the console log output to a div javascript basic test array and loop how to join an array in javascript using the join method show the current date in javascript get element by id and hide it get element by id with javascript set a cookie on click and then check if the cookie is set and dont show that message again console table rather than console log for javascript objects and arrays
Search Code
Search Code by entering your search text above.
Welcome

This is my test area for webdev. I keep a collection of code here, mostly for my reference. Also if i find a good link, i usually add it here and then forget about it. more...

Subscribe to weekly updates about things i have added to the site or thought interesting during the last week.

You could also follow me on twitter or not... does anyone even use twitter anymore?

If you found something useful or like my work, you can buy me a coffee here. Mmm Coffee. ☕

❤️👩‍💻🎮

🪦 2000 - 16 Oct 2022 - Boots
Random Quote
I'm a big believer in energy and the secret and that sort of thing.
Unknown
Random CSS Property

:invalid

The :invalid CSS pseudo-class represents any <input> or other <form> element whose contents fail to validate.
:invalid css reference