first of all I like to clarify that The Problem Domain Is The Hardest Part Of Programming.
A problem domain is the area of expertise or application that needs to be examined to solve a problem. A problem domain is simply looking at only the topics of an individual’s interest, and excluding everything else.
Why problem domains are hard ?
Writing code is a lot like putting together a jigsaw puzzle. We put together code with the purpose of building components that we have taken out of the “bigger picture” of the problem domain.
The big issue is that many problem domains are like a puzzle with a blurry picture or no picture at all.
Objects, in JavaScript, is it’s most important data-type and forms the building blocks. These objects are different from JavaScript’s primitive data-types(Number, String, Boolean, null, undefined and symbol) in the sense that while these primitive data-types all store a single value each (depending on their types).
An object can be created with figure brackets {…} with an optional list of properties. A property is a “key: value” pair, where a key is a string (also called a “property name”), and value can be anything.
When a web page is loaded, the browser creates a Document Object Model of the page.
The HTML DOM model is constructed as a tree of Objects:
What is the HTML DOM? The HTML DOM is a standard object model and programming interface for HTML. It defines:
In other words: The HTML DOM is a standard for how to get, change, add, or delete HTML elements.