DOM | Document Object Model

As the name suggests, in this article we talk about DOM stands for Document object model (DOM). In DOM we discuss it’s properties and programmatical methods that are used for manipulating the document.

Table of Contents

Introduction Document Object Model | What is a DOM

In this dom tutorial, DOM or document object model is an application programming interface (API) for HTML and XML (Xtensible Markup Language) documents.
It defines the logical structure of the documents and the way that the document is accessed by Javascript DOM.
It’s a structure called logical structure because they have no relations between objects.
With DOM we have easy access and manipulate the HTML tags, IDs, classes, attributes or properties using predefined DOM methods or functions.

Structure of the Document Object Model

As the above discussion, the DOM has a logical structure that looks like a tree structure. We prove that statement using a Form a DOM example where we apply DOM methods.

All working the same on the document model in javascript.

Image Reference: https://www.geeksforgeeks.org

Check if JavaScript variable is NULL or Undefined

In the above picture, the properties of document objects are accessed by the document object method.

Window Object: Window object is always on the top of the hierarchy.
Document Object: When HTML is loaded on a window it becomes a document object.
Link Object: Link objects represents by link tags in HTML.
Form Object: Form objects defined by Form tag in HTML.
Anchor Objects: It represents <a href=" "> tag.
Form Elements: Form can have many control elements like textarea, checkboxes, radio buttons, etc.

DOM Object Methods

document.write(“string”): writes the given string on the document
document.getElementById(): returns the element having the given id value.
document. getElementsByName(): returns all the elements having the given name value.
document.getElementsByTagName(): returns all the elements having the given tag name.
document.getElementsByClassName(): returns all the elements having the given class name.