Jun 9, 2023 · This PHP tutorial, whether you’re a beginner or a professional, our tutorial is designed to provide you with in-depth knowledge of the PHP scripting language. With our PHP tutorial, you’ll learn all the important topics, including control statements, functions, arrays, strings, file handling, form handling, regular expressions, date and ... Formatter. This PHP formatter allows you to make your code readable so you can edit it in a more simple fashion. Autodetect HTML XML CSS JavaScript PHP JSON. xxxxxxxxxx. 1. Tab size. Jul 13, 2023 · PHP Exercises, Practice, Solution: PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML. To change the PHP settings, open your User or Workspace Settings ( ⌘, (Windows, Linux Ctrl+,)) and type 'php' to filter the list of available settings. To set the PHP executable path, select the Edit in settings.json link under PHP > Validate: Executable Path, which will open your user settings.json file.PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML.Aug 1, 2023 · Relating to the mb_ucwords() function posted by Anonymous. In order for this to actually be multi-byte compliant, you would also need to use mb_substr() and mb_strlen() instead of substr and strlen respectively. PHP is a server scripting language, and a powerful tool for making dynamic and interactive Web pages. PHP is a widely-used, free, and efficient alternative to competitors such as Microsoft's ASP. Start learning PHP now » Easy Learning with "PHP Tryit"Aug 1, 2023 · PHP tags. When PHP parses a file, it looks for opening and closing tags, which are <?php and ?> which tell PHP to start and stop interpreting the code between them. . Parsing in this manner allows PHP to be embedded in all sorts of different documents, as everything outside of a pair of opening and closing tags is ignored by the PHP par 在 PHP 中，赋值运算符 = 用于给变量赋值。 在 PHP 中，算术运算符 + 用于把值加在一起。 PHP 算术运算符 运算符 名称 描述 实例 结果 x + y 加 x 和 y 的和 2 + 2 4 x - y 减 x 和 y 的差 5 - 2 3 x * y 乘 x 和 y 的积 5 * 2 10 x / y 除 x 和 y 的商 15 /..pub 2048R/31CBD89E 2016-12-08 Key fingerprint = 5289 95BF EDFB A719 1D46 839E F9BA 0ADA 31CB D89E uid Joe Watkins <[email protected]> pub rsa4096 2021-04-26 [SC] [expires: 2025-11-24] 39B6 4134 3D8C 104B 2B14 6DC3 F9C3 9DC0 B969 8544 uid [ultimate] Ben Ramsey <[email protected]> sub rsa4096 2021-04-26 [E] [expires: 2025-11-24] pub rsa4096 2021-04-01 [SC] F1F6 9223 8FBC 1666 E5A5 CCD4 199F 9DFE F6FF ...php 是一种创建动态交互性站点的强有力的服务器端脚本语言。 php 是免费的，并且使用非常广泛。同时，对于像微软 asp 这样的竞争者来说，php 无疑是另一种高效率的选项。 适用于php初学者的学习线路和建议. php 开发工具推荐. php 在线工具 A comment in PHP code is a line that is not executed as a part of the program. Its only purpose is to be read by someone who is looking at the code. Comments can be used to: Let others understand your code. Remind yourself of what you did - Most programmers have experienced coming back to their own work a year or two later and having to re ... Select Data From a MySQL Database. The SELECT statement is used to select data from one or more tables: SELECT column_name (s) FROM table_name. or we can use the * character to select ALL columns from a table: SELECT * FROM table_name. To learn more about SQL, please visit our SQL tutorial. Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML and more. Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML and more.Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures FunctionsPHP $_GET. PHP $_GET is a PHP super global variable which is used to collect form data after submitting an HTML form with method="get". $_GET can also collect data sent in the URL. Assume we have an HTML page that contains a hyperlink with parameters: There is also something called a nowdoc which is like a single quote string in PHP, but these won't let you use variables inside them. It is the start of a string that uses the HEREDOC syntax. A third way to delimit strings is the heredoc syntax: <<<. After this operator, an identifier is provided, then a newline.www.php.net – PHP distribution, tutorials, newsgroups, and more. www.phpfreaks.com - PHP and MySQL tutorials, scripts, forums, and more. www.phpbuilder.com – Collection of PHP resources. Hello World If your web server supports PHP, type this example into a text file called hello.php and access it in your browser bywww.php.net – PHP distribution, tutorials, newsgroups, and more. www.phpfreaks.com - PHP and MySQL tutorials, scripts, forums, and more. www.phpbuilder.com – Collection of PHP resources. Hello World If your web server supports PHP, type this example into a text file called hello.php and access it in your browser byPHP: PHP 8.0.0 Release Announcement. PHP 8.1.23 Released! Change language: Released! PHP 8.0 is a major update of the PHP language. It contains many new features and optimizations including named arguments, union types, attributes, constructor property promotion, match expression, nullsafe operator, JIT, and improvements in the type system ...Configure PHP.ini to display all errors. If adding some of the PHP code errors doesn’t show in the browser during testing, then the PHP ini configuration has some additional directives to handle this. display_errors = on. The display_errors directive must be set to “on” in the PHP ini file.PHP Exercises, Practice, Solution: PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML.Reverse-indent, PHP close tag." Where you see ['dollar-sign' | 'Object-marker'], just choose whichever you tend to speak for '$', I switch between the two frequently, just depends on my audience. So, to sum it up, in PHP, -> refers to a member of an object, be it either a variable, another object, or a method. Practice is key to mastering coding, and the best way to put your PHP knowledge into practice is by getting practical with code. Use W3Schools Spaces to build, test and deploy code. The code editor lets you write and practice different types of computer languages. It includes PHP, but you can use it for other languages too.Ada 6 Jenis operator dalam pemrograman PHP yang harus kita ketahui: Operator Aritmatika; Operator Penugasan atau Assignment; Operator Increment & Decrement; Operator Relasi atau pembanding; Operator Logika; Operator Bitwise; dan Operator Ternary. Mari kita bahas satu persatu….Reverse-indent, PHP close tag." Where you see ['dollar-sign' | 'Object-marker'], just choose whichever you tend to speak for '$', I switch between the two frequently, just depends on my audience. So, to sum it up, in PHP, -> refers to a member of an object, be it either a variable, another object, or a method.Formatter. This PHP formatter allows you to make your code readable so you can edit it in a more simple fashion. Autodetect HTML XML CSS JavaScript PHP JSON. xxxxxxxxxx. 1. Tab size. Mar 15, 2022 · There are two main ways to install PHP on a Windows®-based computer: download the Windows Installer or use the Windows Zip file from the PHP Web site. Either method will get PHP working, but both have some extra steps that are needed to make PHP work well. Windows Installer www.php.net – PHP distribution, tutorials, newsgroups, and more. www.phpfreaks.com - PHP and MySQL tutorials, scripts, forums, and more. www.phpbuilder.com – Collection of PHP resources. Hello World If your web server supports PHP, type this example into a text file called hello.php and access it in your browser byPHP Variables. A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume). A variable starts with the $ sign, followed by the name of the variable. A variable name must start with a letter or the underscore character. A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9 ...Sep 13, 2010 · There is also something called a nowdoc which is like a single quote string in PHP, but these won't let you use variables inside them. It is the start of a string that uses the HEREDOC syntax. A third way to delimit strings is the heredoc syntax: <<<. After this operator, an identifier is provided, then a newline. FastCGI Process Manager (FPM) Installation. Configuration. Installation of PECL extensions. Introduction to PECL Installations. Downloading PECL extensions. Installing a PHP extension on Windows. Compiling shared PECL extensions with the pecl command. Compiling shared PECL extensions with phpize.PHP - Wikipedia. Toggle History subsection. 客家語/Hak-kâ-ngî. 閩東語 / Mìng-dĕ̤ng-ngṳ̄. Oʻzbekcha / ўзбекча. [7] [2] [8] PHP is a general-purpose scripting language geared towards web development. [9] It was originally created by Danish-Canadian Rasmus Lerdorf in 1993 and released in 1995. [10] [11] The PHP reference ...Just like any other programming language, PHP also supports various types of operations like arithmetic operations (addition, subtraction, etc), logical operations (AND, OR etc), Increment/Decrement Operations, etc. Thus, PHP provides us with many operators to perform such operations on various operands or variables, or values.In this tutorial, you’ll create a user registration form that consists of the following input fields: Username. Email. Password. Password confirmation. Agreement checkbox. Register button. When a user fills out the form and click the Register button, you need to: Sanitize & validate the user inputs.Mar 15, 2022 · There are two main ways to install PHP on a Windows®-based computer: download the Windows Installer or use the Windows Zip file from the PHP Web site. Either method will get PHP working, but both have some extra steps that are needed to make PHP work well. Windows Installer A comment in PHP code is a line that is not executed as a part of the program. Its only purpose is to be read by someone who is looking at the code. Comments can be used to: Let others understand your code. Remind yourself of what you did - Most programmers have experienced coming back to their own work a year or two later and having to re ...Aug 1, 2023 · FastCGI Process Manager (FPM) Installation. Configuration. Installation of PECL extensions. Introduction to PECL Installations. Downloading PECL extensions. Installing a PHP extension on Windows. Compiling shared PECL extensions with the pecl command. Compiling shared PECL extensions with phpize. May 30, 2023 · Great if you like your tutorials to the point. 11. Learn-php.org Free Interactive PHP Tutorial. Learn-php.org free interactive PHP tutorial. The unique thing about this PHP tutorial is that it’s a set of interactive exercises that encourage you to try out coding and see if you can get the expected output. PHP can create, open, read, write, delete, and close files on the server. PHP can collect form data. PHP can send and receive cookies. PHP can add, delete, modify data in your database. PHP can be used to control user-access. PHP can encrypt data. With PHP you are not limited to output HTML. You can output images or PDF files. Dec 23, 2022 · The Definitive PHP 7.2, 7.3, 7.4, 8.0, and 8.1 Benchmarks (2023) The year 2021 has been highly eventful for PHP ( and Kinsta ). PHP 8.0 is already a year old, and the much-anticipated PHP 8.1 was released on November 25, 2021, bringing many exciting features. You can catch up on all the latest PHP 8.1 features in our in-depth post. Our basic PHP website is going to feature a home page, including biographical information and some images. For this simple PHP website, you're going to create a single PHP page populated by content from three HTML pages. The index.php file you create can then be edited by adjusting the words and images from the original HTML files.Select Data From a MySQL Database. The SELECT statement is used to select data from one or more tables: SELECT column_name (s) FROM table_name. or we can use the * character to select ALL columns from a table: SELECT * FROM table_name. To learn more about SQL, please visit our SQL tutorial. Here we would like to show the very basics of PHP in a short, simple tutorial. This text only deals with dynamic web page creation with PHP, though PHP is not only capable of creating web pages. See the section titled What can PHP do for more information. PHP-enabled web pages are treated just like regular HTML pages and you can create and edit ...Assignment Operators. ¶. The basic assignment operator is "=". Your first inclination might be to think of this as "equal to". Don't. It really means that the left operand gets set to the value of the expression on the right (that is, "gets set to"). The value of an assignment expression is the value assigned.Download Source Code. This photo editing application is one of those elegantly powerful PHP project ideas that blend JavaScript and PHP to produce a web app for users to create beautiful digital artwork. This PHP project also forces you to use object-oriented programming, which is a great way to hone these skills. Where src/ is the directory containing all your PHP code. Then, run the commands to build and run the Docker image: $ docker build -t my-php-app . $ docker run -d --name my-running-app my-php-app. We recommend that you add a php.ini configuration file; see the "Configuration" section for details. Aug 1, 2023 · Assignment Operators. ¶. The basic assignment operator is "=". Your first inclination might be to think of this as "equal to". Don't. It really means that the left operand gets set to the value of the expression on the right (that is, "gets set to"). The value of an assignment expression is the value assigned. Note that the ; is redundant; as the answers suggest this short-tag expands to an echo with a semicolon added to the end, as per the php documents. – not-just-yeti Oct 5, 2015 at 1:25 PHP $_GET. PHP $_GET is a PHP super global variable which is used to collect form data after submitting an HTML form with method="get". $_GET can also collect data sent in the URL. Assume we have an HTML page that contains a hyperlink with parameters: This PHP formatter allows you to make your code readable so you can edit it in a more simple fashion. Autodetect HTML XML CSS JavaScript PHP JSON. xxxxxxxxxx. 1. Tab size.Sep 3, 2023 · PHP로 작성된 프로그램 목록. 1. 개요 [편집] 대표적인 서버 사이드 스크립트 언어 로 전 세계 수많은 웹 시스템의 기반이 되는 언어. 비슷한 언어로는 Perl, Ruby 등이 있다. C-like 문법 [3] 으로 되어 있고, CGI보다 나으며, Perl처럼 배열이 연관 배열이라 자료 구조가 ... Required Knowledge. Before you begin this PHP tutorial, it is necessary that you have a basic understanding and experience of the following: HTML - PHP can be written with HTML, so it's essential. Basic programming knowledge - If you have any traditional programming experience like C, then learning PHP will be very easy for you.PHP 8.3.0 RC 1 available for testing. Predefined Variables. Predefined Exceptions. Predefined Interfaces and Classes. Predefined Attributes. Supported Protocols and Wrappers. Variable and Type Related Extensions. "MyClass::myFunc () ""OtherClass::myFunc () ". A class constant, class property (static), and class function (static) can all share ...The main PHP configuration file is well-documented and located at /etc/php/php.ini . It is recommended to set your timezone ( list of timezones) in /etc/php/php.ini like so: date.timezone = Europe/Berlin. If you want to display errors to debug your PHP code, change display_errors to On in /etc/php/php.ini: PHP: Hypertext Preprocessor. popular general-purpose scripting language that is especially suited to web development. Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world. What's new in 8.2 Download. 8.2.9 · Changelog · Upgrading.Use W3Schools Spaces to build, test and deploy code. The code editor lets you write and practice different types of computer languages. It includes PHP, but you can use it for other languages too. New languages are added all the time: Learn More. Mar 15, 2022 · There are two main ways to install PHP on a Windows®-based computer: download the Windows Installer or use the Windows Zip file from the PHP Web site. Either method will get PHP working, but both have some extra steps that are needed to make PHP work well. Windows Installer May 29, 2023 · Factors to Consider When Choosing a PHP Framework. Best PHP Frameworks in 2023 (Comparison Table) 10 Best PHP Frameworks in 2023 (Ranked) Laravel. Symfony. Yii 2. CakePHP. CodeIgniter. Zend Framework. A session is started with the session_start () function. Session variables are set with the PHP global variable: $_SESSION. Now, let's create a new page called "demo_session1.php". In this page, we start a new PHP session and set some session variables: لغة PHP (والتي هي اختصارٌ تعاودي للعبارة PHP: Hypertext Preprocessor) هي لغةٌ مفتوحة المصدر شائعة الاستخدام لها مجال استخدامٍ عامٍ لكنها تناسب تطوير الويب ودمج لغة HTML معها. الذي يُميّز PHP عن الشيفرات التي ... PHP - Wikipedia. Toggle History subsection. 客家語/Hak-kâ-ngî. 閩東語 / Mìng-dĕ̤ng-ngṳ̄. Oʻzbekcha / ўзбекча. [7] [2] [8] PHP is a general-purpose scripting language geared towards web development. [9] It was originally created by Danish-Canadian Rasmus Lerdorf in 1993 and released in 1995. [10] [11] The PHP reference ...www.php.net – PHP distribution, tutorials, newsgroups, and more. www.phpfreaks.com - PHP and MySQL tutorials, scripts, forums, and more. www.phpbuilder.com – Collection of PHP resources. Hello World If your web server supports PHP, type this example into a text file called hello.php and access it in your browser byDescription ¶. $_SERVER is an array containing information such as headers, paths, and script locations. The entries in this array are created by the web server, therefore there is no guarantee that every web server will provide any of these; servers may omit some, or provide others not listed here. However, most of these variables are ...A comment in PHP code is a line that is not executed as a part of the program. Its only purpose is to be read by someone who is looking at the code. Comments can be used to: Let others understand your code. Remind yourself of what you did - Most programmers have experienced coming back to their own work a year or two later and having to re ... Jan 30, 2023 · 8.1. Release Date 2021-11-25. Version Status Supported. PHP 8.1, released in 2021, brings major new features such as Enums, Fibers, never return type, Intersection Types, readonly properties, and more, while ironing out some of its undesired legacy features by deprecating them. A comment in PHP code is a line that is not executed as a part of the program. Its only purpose is to be read by someone who is looking at the code. Comments can be used to: Let others understand your code. Remind yourself of what you did - Most programmers have experienced coming back to their own work a year or two later and having to re ... PHP - Keep The Values in The Form. To show the values in the input fields after the user hits the submit button, we add a little PHP script inside the value attribute of the following input fields: name, email, and website. In the comment textarea field, we put the script between the <textarea> and </textarea> tags. PHP: Hypertext Preprocessor. popular general-purpose scripting language that is especially suited to web development. Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world. What's new in 8.2 Download. 8.2.9 · Changelog · Upgrading. In this tutorial, you’ll create a user registration form that consists of the following input fields: Username. Email. Password. Password confirmation. Agreement checkbox. Register button. When a user fills out the form and click the Register button, you need to: Sanitize & validate the user inputs. PHP Operators. PHP Operator is a symbol i.e used to perform operations on operands. In simple words, operators are used to perform operations on variables or values. لغة PHP (والتي هي اختصارٌ تعاودي للعبارة PHP: Hypertext Preprocessor) هي لغةٌ مفتوحة المصدر شائعة الاستخدام لها مجال استخدامٍ عامٍ لكنها تناسب تطوير الويب ودمج لغة HTML معها. الذي يُميّز PHP عن الشيفرات التي ...Tutorial PHP #01: Mengenal Bahasa Pemrograman PHP. Tutorial PHP #02: Persiapan Pemrograman PHP di Linux. Tutorial PHP #02: Persiapan Pemrograman PHP di Linux dengan XAMPP. Tutorial PHP #02: Persiapan Pemrograman PHP di Windows. Tutorial PHP #03: Memahami Struktur Dasar Sintaks PHP. Tutorial PHP #04: Mengenal Fungsi untuk Mencetak Teks.Sep 28, 2020 · A PHP framework is a platform to create PHP web applications. PHP frameworks provide code libraries for commonly used functions, cutting down on the amount of original code you need to write. There are many good reasons for using PHP frameworks as opposed to coding from scratch. Because PHP frameworks have built-in libraries and tools, the time ... PHP로 작성된 프로그램 목록. 1. 개요 [편집] 대표적인 서버 사이드 스크립트 언어 로 전 세계 수많은 웹 시스템의 기반이 되는 언어. 비슷한 언어로는 Perl, Ruby 등이 있다. C-like 문법 [3] 으로 되어 있고, CGI보다 나으며, Perl처럼 배열이 연관 배열이라 자료 구조가 ...Practice is key to mastering coding, and the best way to put your PHP knowledge into practice is by getting practical with code. Use W3Schools Spaces to build, test and deploy code. The code editor lets you write and practice different types of computer languages. It includes PHP, but you can use it for other languages too.Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML and more.Where src/ is the directory containing all your PHP code. Then, run the commands to build and run the Docker image: $ docker build -t my-php-app . $ docker run -d --name my-running-app my-php-app. We recommend that you add a php.ini configuration file; see the "Configuration" section for details. Ada 6 Jenis operator dalam pemrograman PHP yang harus kita ketahui: Operator Aritmatika; Operator Penugasan atau Assignment; Operator Increment & Decrement; Operator Relasi atau pembanding; Operator Logika; Operator Bitwise; dan Operator Ternary. Mari kita bahas satu persatu….Where src/ is the directory containing all your PHP code. Then, run the commands to build and run the Docker image: $ docker build -t my-php-app . $ docker run -d --name my-running-app my-php-app. We recommend that you add a php.ini configuration file; see the "Configuration" section for details.The main PHP configuration file is well-documented and located at /etc/php/php.ini . It is recommended to set your timezone ( list of timezones) in /etc/php/php.ini like so: date.timezone = Europe/Berlin. If you want to display errors to debug your PHP code, change display_errors to On in /etc/php/php.ini:Tutorial PHP #01: Mengenal Bahasa Pemrograman PHP. Tutorial PHP #02: Persiapan Pemrograman PHP di Linux. Tutorial PHP #02: Persiapan Pemrograman PHP di Linux dengan XAMPP. Tutorial PHP #02: Persiapan Pemrograman PHP di Windows. Tutorial PHP #03: Memahami Struktur Dasar Sintaks PHP. Tutorial PHP #04: Mengenal Fungsi untuk Mencetak Teks.
Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions. Taivan
PHP - Keep The Values in The Form. To show the values in the input fields after the user hits the submit button, we add a little PHP script inside the value attribute of the following input fields: name, email, and website. In the comment textarea field, we put the script between the <textarea> and </textarea> tags. Mar 20, 2013 · If you find that when you restart your computer, this solution will not work anymore: Set the Path like as following: Step 1 - Click on the Windows icon. Step 2 - Click on the Settings icon. Step 3 - Click on System. Step 4 - Click on About. Step 5 - Click on System info. Step 6 - Click on Advanced system settings. The user friendly PHP online compiler that allows you to Write PHP code and run it online. The PHP text editor also supports taking input from the user and standard libraries. Select Data From a MySQL Database. The SELECT statement is used to select data from one or more tables: SELECT column_name (s) FROM table_name. or we can use the * character to select ALL columns from a table: SELECT * FROM table_name. To learn more about SQL, please visit our SQL tutorial. Basic PHP Syntax. A PHP script can be placed anywhere in the document. The default file extension for PHP files is " .php ". A PHP file normally contains HTML tags, and some PHP scripting code. Below, we have an example of a simple PHP file, with a PHP script that uses a built-in PHP function " echo " to output the text "Hello World!" Download Source Code. This photo editing application is one of those elegantly powerful PHP project ideas that blend JavaScript and PHP to produce a web app for users to create beautiful digital artwork. This PHP project also forces you to use object-oriented programming, which is a great way to hone these skills.PHP frameworks offer several benefits, making them a compelling choice for web developers. Firstly, PHP frameworks offer a structured approach to development with pre-built components, streamlining the process, accelerating project completion, and enhancing productivity. Secondly, using a PHP framework can contribute to cost savings.Arrays. ¶. An array in PHP is actually an ordered map. A map is a type that associates values to keys. This type is optimized for several different uses; it can be treated as an array, list (vector), hash table (an implementation of a map), dictionary, collection, stack, queue, and probably more. As array values can be other array s, trees and ...www.php.net – PHP distribution, tutorials, newsgroups, and more. www.phpfreaks.com - PHP and MySQL tutorials, scripts, forums, and more. www.phpbuilder.com – Collection of PHP resources. Hello World If your web server supports PHP, type this example into a text file called hello.php and access it in your browser by Where src/ is the directory containing all your PHP code. Then, run the commands to build and run the Docker image: $ docker build -t my-php-app . $ docker run -d --name my-running-app my-php-app. We recommend that you add a php.ini configuration file; see the "Configuration" section for details. PHP is a server scripting language, and a powerful tool for making dynamic and interactive Web pages. PHP is a widely-used, free, and efficient alternative to competitors such as Microsoft's ASP. Start learning PHP now » Easy Learning with "PHP Tryit" If you have permission to SSH into the remote server, use the command line to check the installed PHP version. This method is also useful for checking the PHP version installed locally. 1. Type the PHP command: php -v. 2. The php -v command works on Linux, macOS, Windows, and other supported systems. Its output contains the PHP version number ...Variables in PHP are represented by a dollar sign followed by the name of the variable. The variable name is case-sensitive. Variable names follow the same rules as other labels in PHP. A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores..