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Understanding DOM and CSSOM: Problems, Solutions, and Performance Optimizations
Document Object Model(DoM) and CSS Object Model(CSSOM) are fundamental things every developer must know to understand the web. Most developers know the DoM, but very few know about CSSOM.
Understanding DOM and CSSOM helps frontend developers to create dynamic and interactive web applications. Moreover, these are must-to-know topics for your front-end interviews. Let’s explore these two concepts in depth and frequently asked questions in interviews.
What is DOM?
DOM is a programming interface which represents the HTML and XML as a tree of objects. Each element in the document like headings, images, paragraphs,.. are represented as node of this tree. This hierarchical representation simplifies the access and manipulation of the DOM elements.
Node Types:
- Element Nodes: Represent HTML tags (e.g., <div>, <p>).
- Text Nodes: Contain the text within elements.
- Attribute Nodes: Represent attributes of elements (e.g., class, id).
Interview Tip:
As DOM is represented as Tree, most of the PSDS rounds for frontend interviews revolve around trees.
Example
<html>
<head>…
