Dynamic HTML (DHTML) is a combination of technologies used to create interactive and dynamic web content. It’s not a standalone standard or programming language but rather a collection of techniques and tools that work together. DHTML enables websites to update content dynamically and provide interactivity without reloading the entire page.
HTML (Hypertext Markup Language)
Provides the basic structure of the webpage.
CSS (Cascading Style Sheets)
Controls the appearance and layout of the webpage. CSS can be dynamically altered to create effects like hover states or style changes.
JavaScript
Adds interactivity and dynamic behavior, such as updating content without a page reload.
DOM (Document Object Model)
A programming interface that allows access to and manipulation of the webpage’s structure. JavaScript interacts with the DOM to change content or add new elements.
Here’s a simple example of a button changing text dynamically:
<!DOCTYPE html>
<html>
<head>
<style>
#text {
color: blue;
font-size: 20px;
}
</style>
<script>
function changeText() {
document.getElementById("text").innerHTML = "Text changed!";
document.getElementById("text").style.color = "red";
}
</script>
</head>
<body>
<p id="text">Original text</p>
<button onclick="changeText()">Click me</button>
</body>
</html>
Nowadays, DHTML has been largely replaced by modern techniques like AJAX and frameworks (e.g., React, Vue.js). However, it was a crucial step in the evolution of interactive web applications.
The Document Object Model (DOM) is a standardized interface provided by web browsers to represent and programmatically manipulate structured documents, especially HTML and XML documents. It describes the hierarchical structure of a document as a tree, where each node represents an element, attribute, or text.
Tree Structure:
<html>
element, with child nodes such as <head>
, <body>
, <div>
, <p>
, etc.Object-Oriented Representation:
Interactivity:
<p>
element or insert a new <div>
.Platform and Language Agnostic:
1. Accessing an Element:
let element = document.getElementById("myElement");
2. Changing Content:
element.textContent = "New Text";
3. Adding a New Element:
let newNode = document.createElement("div");
document.body.appendChild(newNode);
The DOM is defined and maintained by the W3C (World Wide Web Consortium) standards and is constantly updated to support modern web technologies.
Markdown is a lightweight markup language designed to create easily readable and simultaneously formattable text. It is often used to format text in websites, documentation, and other text-based formats. Markdown files use the .md
or .markdown
file extension.
Here are some basic elements of Markdown:
Headings:
# Heading 1
## Heading 2
### Heading 3
Text Formatting:
*italic*
or _italic_
**bold**
or __bold__
~~strikethrough~~
Lists:
* Item 1
* Item 2
1. Item 1
2. Item 2
Links:
[Link text](URL)
Images:
![Alt text](Image URL)
Code:
`code`
Blockquotes:
> This is a quote
Horizontal Line:
---
or ***
Markdown is particularly useful because it is easily readable even when not rendered. This makes it ideal for use in versioning and collaboration systems like GitHub, where users can directly view and edit text files.
XHTML (Extensible Hypertext Markup Language) is a variant of HTML (Hypertext Markup Language) that is based on XML (Extensible Markup Language). XHTML combines the flexibility of HTML with the strictness and structure of XML. Here are some key aspects and features of XHTML:
Structure and Syntax:
<p></p>
) or as self-closing tags (e.g., <img />
).Compatibility:
Doctype Declaration:
Practical Use:
Different XHTML Profiles:
In summary, XHTML is a stricter and more structured variant of HTML based on XML, offering advantages in certain application areas. It was developed to improve web interoperability and standardization but has not been fully adopted due to the advent of HTML5.
XML stands for "eXtensible Markup Language" and is a widely used language for structuring and presenting data. Essentially, XML is used to organize information in a formatted, hierarchical manner. It's similar to HTML but much more flexible, allowing for the creation of custom tags to label specific types of data.
XML finds applications in various fields such as:
Web Development: Used for data transmission between different systems or configuring web services.
Databases: Facilitates data exchange between different applications or for storing structured data.
Configuration Files: Many software applications use XML files to store settings or configurations.
Document Exchange: Often used to exchange structured data between different platforms and applications.
XML uses tags similar to HTML to organize data. These tags are used in pairs (opening and closing tags) to denote the beginning and end of a particular data component. For example:
<Person>
<Name>Max Mustermann</Name>
<Age>30</Age>
<Address>
<Street>Main Street</Street>
<City>Example City</City>
</Address>
</Person>
Here, a simple XML structure is articlen containing information about a person including name, age, and address.
XML provides a flexible way to structure and store data, making it an essential tool in information processing and data exchange.
HTML stands for "Hypertext Markup Language" and is a markup language used to structure content on the web. It serves as a foundation for web development, describing and organizing the content of a web page. HTML uses tags or markup to identify and structure different elements on a webpage.
A basic HTML document consists of HTML tags marking the beginning and end of elements. Here's an example of the basic structure of an HTML document:
<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
</head>
<body>
<h1>Heading 1</h1>
<p>This is a paragraph.</p>
<!-- More HTML elements here -->
</body>
</html>
Here are some basic HTML elements:
<html>
: The root element that wraps around the entire HTML content.<head>
: Contains meta-information about the HTML document, such as the page title, references to CSS files, etc.<title>
: Defines the title of the webpage displayed in the browser tab.<body>
: Contains the actual content of the webpage, such as text, images, links, etc.<h1>
, <h2>
, <h3>
, ..., <h6>
: Headings of different hierarchy levels.<p>
: A paragraph.<!-- comment -->
.HTML is often used in conjunction with CSS (Cascading Style Sheets) and JavaScript to not only structure content but also to style and provide interactivity to web pages.