Lesson 17 of 3352%

(Progress persistence is disabled until Phase 9)

JavaScript
Intermediate
20 min

Introduction to the DOM

Understand the Document Object Model.

Learning Objectives

  • The window and document objects

Introduction to the DOM

Welcome to this lesson on Introduction to the DOM. JavaScript is the programming language of the web, and introduction to the dom is a fundamental piece of that ecosystem.

Explanation

When your browser loads a web page, the HTML creates the structure, the CSS creates the style, and JavaScript creates the interactivity. JavaScript can update both HTML and CSS in real-time.

Code Examples

Here is a simple snippet demonstrating this concept:

const newDiv = document.createElement("div");
body.appendChild(newDiv);\n```

### Explanation of Code

In the example above, we define the logic required to implement the concept, and then execute it. The JavaScript engine parses this syntax and runs it.

<Callout type="warning">
**Common Mistake:** Watch out for syntax errors! Missing a bracket or a semicolon can sometimes break your entire script.
</Callout>

### Try It Yourself

Put this into practice! The BrowserCode runtime allows you to execute JavaScript securely in your browser.

<TryItButton />

### Key Takeaways
- JavaScript makes pages interactive.
- Always check your browser console for errors.

Lesson Progress

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