Introduction to the basics of HTML: The skeleton of every website

HTML, the abbreviation for Hypertext Markup Language, is the basic building block language of the Internet and is essential for creating websites. As a structured language, HTML enables the definition of website content and its semantic organization through tags and elements.

Structure of an HTML page

An HTML page begins with the document type declaration tag which tells the browser that it is an HTML5 page. This is followed by the -element, which marks the beginning and end of the HTML document. Within the -tag contains the -element, which contains metadata such as the title and links to CSS files, and the -element, which contains the visible content of the page.

Semantic structuring in HTML

Tags such as < header >, < footer >, < article > and < section > are essential for structuring the conent. These semantic elements help to structure the website logically and optimized for search engines. The < header > for example, often contains the navigation and logo, while the < footer > can contain contact information and legal information.

Lists and graphics in HTML

Lists are created with < ul > for unordered lists or < ol > for ordered lists, whereby each list element is located within an < li > tag. The < img > tag is responsible for images and graphics and i equipped with attributes such as “src” for the image source and “alt” for the alternative text.

Hyperlinks and the networking of websites

Hyperlinks, which form the basic structure of the Internet, are created with the < a > tag. The href attribute of this tag determines the destination of the link. The ability to create links is one of the most powerful functions of HTML, as it enables the linking of resources on the Internet.

Importance of HTML in web development

Mastering HTML is the first step to professional web design and development, and a deep understanding of this language is essential for any web developer. By combining HTML with CSS and JavaScript, developers can create functional, stylish and interactive websites.

CSS for beginners: personalize the style and design of your website

CSS, or Cascading Style Sheets, is a style language used to design the appearance and layout of websites created with HTML. It allows developers and designers to control the design of multiple websites through centralized style sheets, which facilitates consistent design.

The basic concept of CSS is the separation of content (HTML) and design (CSS) in order to make web development more efficient and flexible. CSS rules consist of a selector and a declaration block. The selector targets the HTML element that is to be designed, while the declaration block defines the style properties that are to be applied.

For example, the CSS rule

h1 {
color: navy;
font-size: 24px;
}

determines the color and font size of all < h1 > tags on a web page. Such rules can be saved in a < style > tag in the < head > are of the HTML document or in an external CSS file that is integrated via the < link > tag.

CSS offers a variety of properties such as margin, padding, border, and background that control the box model of web pages. These properties help to manipulate the space around and between the elements. Also important are the positioning properties such as position, top, right, bottom, and left, which determine where an element is placed on the page.

Modern CSS frameworks such as Bootstrap offer predefined styles and components that can simplify web design. However, understanding the basic CSS principles is crucial in order to use such frameworks effectively and adapt them as required.

By mastering CSS, you can not only increase the visual quality of your websites, but also create a better user experience. This is a crucial factor for the success of any website.

JavaScript Essentials: Interactivity and dynamics made easy

JavaScript is a powerful, object-oriented scripting language that enables websites to be designed interactively. In contrast to HTML and CSS, which are responsible for structure and design, JavaScript enables the creation of dynamic interactions, such as responding to user input, manipulating website elements in real time and communicating with servers without page reloads.

Example for JavaScript

A simple example of JavaScript is displaying a pop-up message when a user loads a web page:

window.onload = function() {
alert(‘Welcome to our website!’);
};

These lines of code bind a function to the page load event, which displays a dialog box with a message. Such event-controlled functions are central to the dynamic functionality of websites.

JavaScript and HTML

JavaScript can also be used to manipulate HTML elements directly. The Document Object Model (DOM) is a programmable interface for HTML and XML documents, and JavaScript provides functions to browse and modify the DOM. For example, you can change the content of an HTML element:

document.getElementById(‘demo’).innerHTML = ‘Hello world!

This line of code finds an element with the ID “demo” and sets its content to “Hello world!”. This ability to manipulate the DOM makes JavaScript extremely powerful for the development of interactive user interfaces.

JavaScript also makes it possible to interact with external APIs and data sources, which is essential for modern web applications such as single page applications (SPAs). AJAX (Asynchronous JavaScript and XML) is a technique that allows data to be sent and received from a server without having to reload the entire page.

Mastering JavaScript opens the door to advanced web technologies and frameworks that enable the development of professional and highly interactive websites.

Combination of HTML, CSS and JavaScript: Creating interactive websites

The combination of HTML, CSS and JavaScript is the key to creating modern and interactive websites. HTML defines the structure, CSS takes care of the design and JavaScript adds interactivity. Together, these three technologies enable web developers to create seamless and dynamic user experiences.

1. a simple example: start with HTML

Let’s start with a basic example: a web page that displays a registration form. HTML is used to structure the form and its fields. A typical form could look like this:

< form >
< label for=”username” > username: < / label >
< input type=”text” id=”username” name=”username” >
< label for=”password” > Password: < / label >
< input type=”password” id=”password” name=”password” >
< button type=”submit” > log in < / button >
< / form >

2. use CSS

CSS is then used to make the form visually appealing. For example, you could stylize the text fields and the button to make them stand out:

input[type="text"], input[type="password"] {
    width: 100%;
    padding: 8px;
    margin: 10px 0;
}

button {
    background-color: blue;
    color: white;
    padding: 10px 15px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

3. add JavaScript

Finally, JavaScript adds the required functionality, e.g. checking the input before the form is sent:

document.querySelector('form').onsubmit = function(event) {
    if (document.getElementById('username').value === '' || document.getElementById('password').value === '') {
        alert('Please fill out both fields!');
        event.preventDefault();
    }
};

This simple combination of the three technologies results in a functional and aesthetically pleasing website. Web developers use this synergy to develop complex applications that are feature-rich and intuitive to use. Advanced topics such as responsive design and AJAX interactions are also possible through the skillful use of HTML, CSS and JavaScript, opening the door to almost limitless possibilities in web development.

PHP basics: Understanding and using server-side scripts

PHP (Hypertext Preprocessor) is a widely used server-side scripting language designed specifically for web development, but is also used as a general programming language. This code is executed on the server and the result is then sent to the user’s browser as simple HTML.

PHP script

A simple PHP script begins with the tags <?php and ends with ?>. The PHP code is written within these tags. A basic example of PHP could be the output of “Hello world”:

<?php
echo 'Hello World!';
?>

This code is executed on the server and sends the words “Hello world!” to the browser, where they are displayed as part of an HTML page. PHP can also be used to process data from forms, interact with databases and manage user sessions.

PHP and databases

A key aspect of PHP is its ability to interact with databases, which makes it ideal for creating dynamic websites. PHP works extremely well with MySQL, one of the most popular database management systems on the web. For example, a PHP script can be designed to retrieve user information from a database:

<?php
$mysqli = new mysqli("Beispielhost", "Benutzername", "Passwort", "Datenbankname");
$result = $mysqli->query("SELECT * FROM users");
while ($row = $result->fetch_assoc()) {
    echo $row['username'] . '<br>';
}
?>

This script establishes a connection to a MySQL database, executes an SQL query that retrieves all users from the users table and displays the user names on the web page.

PHP is also known for its use of sessions, which allow information to be stored across multiple page views by a user. This is useful for functions such as user logins and saving shopping carts in online stores.

Learning PHP opens the door to a wide range of web development possibilities, from simple websites to complex applications, and remains one of the pillars of server-side web development.

From frontend to backend: How PHP enhances the web experience

PHP (Hypertext Preprocessor) is a key component in the world of web development, especially when it comes to the backend, i.e. server-side development. While HTML, CSS and JavaScript are mainly executed on the client, i.e. in the user’s browser, and design the front end, PHP enables the creation of dynamic and interactive websites through its capabilities on the server side.

Integrating PHP into HTML

One of the main features of PHP is its seamless integration into the HTML document. PHP code can be embedded within an HTML document, allowing developers to generate dynamic content directly within the static HTML structure. For example, PHP can be used to display current data such as date and time directly on a web page:

<!DOCTYPE html>
<html>
<head>
    <title>Beispiel Seite</title>
</head>
<body>
    <p>Heutiges Datum: <?php echo date('d.m.Y'); ?></p>
</body>
</html>

This simple code displays the current date in an HTML paragraph. The PHP part is processed on the server, and the result – the current date – is inserted into the HTML document before it is sent to the browser.

Use of PHP

PHP is also widely used to interact with databases such as MySQL. This capability makes it possible to store, retrieve and manipulate data, which is essential for applications such as online stores, forums or social networks. PHP scripts can receive data from users via forms, store this data in a database and retrieve it when needed.

In addition, PHP enables the creation of user-specific experiences, such as personalized greetings or the display of user-relevant data and functions. By using sessions, PHP can identify users across different page views and customize their interactions accordingly.

The combination of front-end technologies and PHP as a back-end solution enables the development of fully functional, dynamic and interactive websites that go beyond what would be possible with pure HTML, CSS and JavaScript. This greatly enhances the web experience by providing deeper interaction and functionality.