In order to use a class, you need to include the file that defines it. Autoloading is a PHP feature that allows your program to search and load files automatically given some set of predefined rules. Each time you reference a class that PHP does not know about, it will ask the autoloader.

There are a lot of situations where you might need to get the URL of a webpage that any user might be currently visiting. For example, you may require you to dynamically generate the title of a webpage based on its URL. There are many ways in which you can obtain the URL of a webpage.

Content events are triggered during the content creation process. The majority of these events are called in many views, many components and modules. They are generally not specific for the com_content component.

An associative array is composed of a collection of key and value pairs. Indexed array is an array with a numeric key.

The General Data Protection Regulation (GDPR) enters into force on 25 May, 2018. Joomla integrates a Privacy Tool Suite in the Joomla CMS to facilitate the compliance of the sites.

Proper structured data in your news, blog, and sports article page can enhance your appearance in Google Search results. Enhanced features include entry in a top stories carousel and rich result features such as headline text and larger-than-thumbnail images. Your content may also be automatically turned into an action on the Google Assistant. 

A breadcrumb trail on a page indicates the page's position in the site hierarchy. A user can navigate all the way up in the site hierarchy, one level at a time, by starting from the last breadcrumb in the breadcrumb trail.

You can display a 2 dimensional array in PHP as a HTML table using nested foreach loop. For example, this is useful when you get rows of information from MySQL, and then you need to display its output as a table.

You can take over control of virtually all the output that is generated by Joomla. Except for files that are provided in the Joomla! distribution itself, overrides or customization eliminate the need to hack core files that could change when the site is updated to a new version.

Databases exist because of the need to change data into information. Data are the raw and unprocessed facts. Information is obtained by processing the data into something useful. A database is a large repository of facts, designed in such a way that processing the facts into information is easy.

A key, or index, unlocks access to the tables. If you know the key, you know how to identify specific records and the relationships between the tables. Each key consists of one or more fields, or field prefix. The order of columns in an index is significant. Each key has a name.

MariaDB is a community-developed fork of the MySQL relational database management system intended to remain free under the GNU GPL. Some of the original developers of MySQL forked it due to concerns over its acquisition by Oracle Corporation. Its lead developer is Michael "Monty" Widenius, one of the founders of MySQL AB. MariaDB is named after Monty's younger daughter Maria, similar to how MySQL is named after his other daughter My.

MySQL is an open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter, and "SQL", the abbreviation for Structured Query Language. MySQL is a component of the LAMP open-source web application software stack. LAMP is an acronym for "Linux, Apache, MySQL, Perl/PHP/Python".

MySQL stores information in different formats. It allows different types of data to be used in different ways. The main types of data are character, numerical, and date and time. When you create a database, you tell MySQL what kind of data to expect in a particular column by using the MySQL names for data types.

A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field. Then, the field will be saved with a NULL value.

If you use Kunena forum extension for Joomla, there is a simple way to remove the footer back link. The following method works for Kunena 5.x and later versions. Follow the steps if it is necessary for you to remove Powered By Kunena Forum Footer Link. This works as of Kunena version 5.0.14.

You may get confused over choosing Windows or Linux as host operating system in both server and desktop spaces. With focus on aspects of cost, the functionality provided, hardware compatibility, support, reliability, security, existing software, and other factors, here are reasons why Linux can be better option than Windows operating system.

Linux is free and open-source, so can simply change anything in Linux. There are several Linux Distributions (also known as distros) - Ubuntu, Red Hat, Mint, Debian, Fedora.

Linux Shell or Terminal

A shell is a program that receives commands from the user and gives it to the OS to process, and then it shows the output. Linux distributions come in GUI (graphical user interface), but Linux has a CLI (command line interface). To open the terminal, press Ctrl+Alt+T in Ubuntu, or press Alt+F2, type in gnome-terminal, and press enter.

If you want all the visitor on the webpage https://example.com/initial.php to redirect to https://example.com/final.php, this can be done using several methods using PHP, JavaScript and HTML.

Calculating the difference between two dates is not as easy as it sounds. There are a lot of things that can go wrong if you are not careful. For example, you have to take both leap years and daylight saving time into consideration. Simply converting two dates to a timestamp and subtracting the values is not reliable in all cases. The PHP DateTime class takes care of all this.

Many times, you have to programmatically resize images. Maybe you have to create multiple sizes of the same image to serve on different devices. Maybe you need to resize images that your users are uploading. You can make use of the PHP’s GD library to resize images in PHP. GD has all the necessary functions to manipulate images so you won’t have to use any other 3rd party library.

Many times, the strings have extra spaces that need to be removed. For example, you might want to replace multiple spaces with a single space or you might want to get rid of all the whitespace in a string. Similarly, you might be planning on stripping all the whitespace from either the left or the right end of a string.

You can upload files on server using a HTML form and PHP. You can upload any kind of file like images, videos, ZIP files, Microsoft Office documents, PDFs, and other files. The uploaded file can be saved in any folder on permanent basis. You can also implement some basic security check like file type and file size to ensure that users upload the correct file type and within the allowed limit.

PHP allows you to work with directories on the file system. For example, you can open a directory and read its contents, create or delete a directory, list all files in the directory, and so on.

PHP 5 introduced new object oriented way of dealing with errors. Exceptions are used to change the normal flow of a script if a specified error occurs. Exception handling is used to change the normal flow of the code execution if a specified error (exceptional) condition occurs. This condition is called an exception.

You can use the array_shift() function to remove the first element or value from an array. The array_shift() function returns the removed first value of array. If the array is empty (or the variable is not an array), the returned value is NULL.

You can use the array_pop() function to remove an element or value from the end of an array. The array_pop() function returns the last value of array. If the array is empty (or the variable is not an array), then the returned value is NULL.

Joomla 4.0 is Joomla’s new major version. Joomla 3.9 is released alongside Joomla 4 as the last minor release of Joomla 3. Joomla 3.9 will continue to be supported for 2 years giving plenty of time to webmasters to plan migration to Joomla 4 and update extensions to Joomla 4 compatible versions.

Joomla! 3.8 is the ninth standard-term support release in the Joomla 3 series. It was released on 19 September, 2017. This release features over 300 improvements to the CMS, with two primary major features aimed at developers: the new routing system and the beginning of a forward compatibility layer with Joomla! 4.0. Additionally, two security issues have been resolved.