The PHP concatenation operator (.) is used to combine two string values to create one string. .=. Concatenation assignment.The POST Method. The POST method transfers information via HTTP headers. The information is encoded as described in case of GET method and put into a header called QUERY_STRING. The POST method does not have any restriction on data size to be sent. The POST method can be used to send ASCII as well as binary data. 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" With our online "PHP Tryit" editor, you can edit the PHP code, and click on a button to view the result. Example Get your own PHP Server <!DOCTYPE html> <html> <body> <?phpPHP is a server side scripting language that is embedded in HTML. It is used to manage dynamic content, databases, session tracking, even build entire e-commerce sites. It is integrated with a number of popular databases, including MySQL, PostgreSQL, Oracle, Sybase, Informix, and Microsoft SQL Server. PHP is pleasingly zippy in its execution ... Aug 1, 2023 · Classes should be defined before instantiation (and in some cases this is a requirement). containing the name of a class is used with , a new instance of that class will be created. If the class is in a namespace, its fully qualified name must be used when doing this. As of PHP 8.0.0, using with arbitrary expressions is supported. 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 ...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" With our online "PHP Tryit" editor, you can edit the PHP code, and click on a button to view the result. Example Get your own PHP Server <!DOCTYPE html> <html> <body> <?php PHP Programming at Wikibooks. PHP is a general-purpose scripting language geared towards web development. [9] It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. [10] [11] The PHP reference implementation is now produced by the PHP Group. [12] PHP was originally an abbreviation of Personal Home ...There are two string operators. The first is the concatenation operator ('.'), which returns the concatenation of its right and left arguments. The second is the concatenating assignment operator (' .= '), which appends the argument on the right side to the argument on the left side. Please read Assignment Operators for more information.Match expressions are available as of PHP 8.0.0. arm compares values strictly () instead of loosely as the switch statement does. expression must be exhaustive. // Is equivalent to these three match arms: Alternative syntax for control structures. do- while. require_ once. include_ once.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. Aug 1, 2023 · Here's how to run dual PHP instances with PHP 5.2 and any previous PHP on Windows 2003: 1. Right-click My Computer, go to Advanced tab, and click on Environment Variables. Add the two installations and their EXT directories to the Path variable. For example, add: c:\php;c:\php\ext;c:\TMAS\php;c:\tmas\php\ext; 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. 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 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.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-GTK related documentation is hosted on the PHP-GTK website. Documentation of PEAR and the various packages can be found on a separate server. You can still read a copy of the original PHP/FI 2.0 Manual on our site, which we only host for historical purposes. The same applies to the PHP 3 Manual .Sep 4, 2023 · 0.01 7649551 US Dollars. 1 USD = 56.6587 PHP. We use the mid-market rate for our Converter. This is for informational purposes only. You won’t receive this rate when sending money. Login to view send rates. Philippine Peso to US Dollar conversion — Last updated Sep 3, 2023, 08:11 UTC. Here's how to run dual PHP instances with PHP 5.2 and any previous PHP on Windows 2003: 1. Right-click My Computer, go to Advanced tab, and click on Environment Variables. Add the two installations and their EXT directories to the Path variable. For example, add: c:\php;c:\php\ext;c:\TMAS\php;c:\tmas\php\ext;The POST Method. The POST method transfers information via HTTP headers. The information is encoded as described in case of GET method and put into a header called QUERY_STRING. The POST method does not have any restriction on data size to be sent. The POST method can be used to send ASCII as well as binary data. PHP Conditional Statements. Very often when you write code, you want to perform different actions for different conditions. You can use conditional statements in your code to do this. In PHP we have the following conditional statements: if statement - executes some code if one condition is trueThe optional timestamp parameter in the date () function specifies a timestamp. If omitted, the current date and time will be used (as in the examples above). The PHP mktime () function returns the Unix timestamp for a date. The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time ...Match expressions are available as of PHP 8.0.0. arm compares values strictly () instead of loosely as the switch statement does. expression must be exhaustive. // Is equivalent to these three match arms: Alternative syntax for control structures. do- while. require_ once. include_ once.PHP 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 ...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 Conditional Statements. Very often when you write code, you want to perform different actions for different conditions. You can use conditional statements in your code to do this. In PHP we have the following conditional statements: if statement - executes some code if one condition is truePHP is a script on the server-side used for the creation of Static or Dynamic Web sites or Web applications. PHP is a pre-processor for hypertext, which used to stand for home pages. The software used to build web applications is an open-source, server-side scripting language. We say a program designed for automated work by writing a script ...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.Aug 1, 2023 · The interactive shell stores your history which can be accessed using the up and down keys. The history is saved in the ~/.php_history file. The CLI SAPI provides the php.ini settings cli.pager and cli.prompt. The cli.pager setting allows an external program (such as less) to act as a pager for the output instead of being displayed directly on ... 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 ... 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 1:25Aug 1, 2023 · Returns the hexadecimal representation of the given string. Examples ¶ Example #1 bin2hex () example <?php $hex = bin2hex('Hello world!'); var_dump($hex); var_dump(hex2bin($hex)); ?> The above example will output: string (24) "48656c6c6f20776f726c6421" string (12) "Hello world!" See Also ¶ hex2bin () - Decodes a hexadecimally encoded binary string PHP Resource. The special resource type is not an actual data type. It is the storing of a reference to functions and resources external to PHP. A common example of using the resource data type is a database call. We will not talk about the resource type here, since it is an advanced topic.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.The optional timestamp parameter in the date () function specifies a timestamp. If omitted, the current date and time will be used (as in the examples above). The PHP mktime () function returns the Unix timestamp for a date. The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time ...InstagramA 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 ...Pengertian PHP. PHP (PHP: Hypertext Preprocessor) adalah sebuah bahasa pemrograman server side scripting yang bersifat open source. Sebagai sebuah scripting language, PHP menjalankan instruksi pemrograman saat proses runtime. Hasil dari instruksi tentu akan berbeda tergantung data yang diproses.PHP is a server-side scripting language, which means that a server executes the instructions in a script. Then, the server provides data on request, channels the requests, and organizes the information in a database. When a web server receives a script, it will process the request and send output to a web browser in an HTML format.MySQL is a database system used on the web. MySQL is a database system that runs on a server. MySQL is ideal for both small and large applications. MySQL is very fast, reliable, and easy to use. MySQL uses standard SQL. MySQL compiles on a number of platforms. MySQL is free to download and use. MySQL is developed, distributed, and supported by ...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. PHP is a general-purpose scripting language widely used as a server-side language for creating dynamic web pages. Though its reputation is mixed, PHP is still extremely popular and is used in over 75% of all websites where the server-side programming language is known.In order to set project specific configuration options, simply add a php.ini file to your project, and then run the built-in server with this flag: php -S localhost:8000 -c php.ini. This is especially helpful for settings that cannot be set at runtime (ini_set ()). up. down.This is an example PHP application, which is intentionally vulnerable to web attacks. It is intended to help you test Acunetix. It also helps you understand how developer errors and bad configuration may let someone break into your website. You can use it to test other tools and your manual hacking skills as well. InstagramPHP is a widely-used, free, and efficient alternative to competitors such as Microsoft's ASP. Start learning PHP now » Easy Learning with "PHP Tryit" With our online "PHP Tryit" editor, you can edit the PHP code, and click on a button to view the result. Example Get your own PHP Server <!DOCTYPE html> <html> <body> <?php Nov 2, 2021 · Pengertian PHP. PHP (PHP: Hypertext Preprocessor) adalah sebuah bahasa pemrograman server side scripting yang bersifat open source. Sebagai sebuah scripting language, PHP menjalankan instruksi pemrograman saat proses runtime. Hasil dari instruksi tentu akan berbeda tergantung data yang diproses. 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 ...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.There are two string operators. The first is the concatenation operator ('.'), which returns the concatenation of its right and left arguments. The second is the concatenating assignment operator (' .= '), which appends the argument on the right side to the argument on the left side. Please read Assignment Operators for more information.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 ... Feb 6, 2023 · How to increase PHP memory_limit. To increase the PHP memory limit setting, edit your PHP.ini file. Increase the default value (example: Maximum amount of memory a script may consume = 128MB) of the PHP memory limit line in php.ini. memory_limit = 1024M. Alternatively, you can edit your .htaccess file (Not recommended. May 29, 2023 · 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. Jan 22, 2009 · 15. According to the article How to Get Current Datetime (NOW) with PHP, there are two common ways to get the current date. To get current datetime (now) with PHP, you can use the date class with any PHP version, or better the datetime class with PHP >= 5.2. Various date format expressions are available here. 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 You can also call the script from the command line after chmod'ing the file (ie: chmod 755 file.php). On your first line of the file, enter "#!/usr/bin/php" (or to wherever your php executable is located). If you want to suppress the PHP headers, use the line of "#!/usr/bin/php -q" for your path. up. down.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.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 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.The optional timestamp parameter in the date () function specifies a timestamp. If omitted, the current date and time will be used (as in the examples above). The PHP mktime () function returns the Unix timestamp for a date. The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time ...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 Partitioning up long code blocks really helps to locate the origin of syntax errors. Comment out offending code. If you can't isolate the problem source, start to comment out (and thus temporarily remove) blocks of code. As soon as you got rid of the parsing error, you have found the problem source. 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 Operators. Operators are used to perform operations on variables and values. PHP divides the operators in the following groups: Arithmetic operators. Assignment operators. Comparison operators. Increment/Decrement operators. Logical operators. String operators.PHP Programming at Wikibooks. PHP is a general-purpose scripting language geared towards web development. [9] It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. [10] [11] The PHP reference implementation is now produced by the PHP Group. [12] PHP was originally an abbreviation of Personal Home ...PHP-GTK related documentation is hosted on the PHP-GTK website. Documentation of PEAR and the various packages can be found on a separate server. You can still read a copy of the original PHP/FI 2.0 Manual on our site, which we only host for historical purposes. The same applies to the PHP 3 Manual .The optional timestamp parameter in the date () function specifies a timestamp. If omitted, the current date and time will be used (as in the examples above). The PHP mktime () function returns the Unix timestamp for a date. The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time ...This is an example PHP application, which is intentionally vulnerable to web attacks. It is intended to help you test Acunetix. It also helps you understand how developer errors and bad configuration may let someone break into your website. You can use it to test other tools and your manual hacking skills as well.Feb 6, 2023 · How to increase PHP memory_limit. To increase the PHP memory limit setting, edit your PHP.ini file. Increase the default value (example: Maximum amount of memory a script may consume = 128MB) of the PHP memory limit line in php.ini. memory_limit = 1024M. Alternatively, you can edit your .htaccess file (Not recommended. Partitioning up long code blocks really helps to locate the origin of syntax errors. Comment out offending code. If you can't isolate the problem source, start to comment out (and thus temporarily remove) blocks of code. As soon as you got rid of the parsing error, you have found the problem source. Dec 1, 2019 · PHP is a server-side scripting language created in 1995 by Rasmus Lerdorf. PHP is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML. What is PHP used for? As of October 2018, PHP is used on 80% of websites whose server-side language is known. It is typically ... 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.2 years ago. In php there are 3 types of comments. 1.single line c++ style comment (//) 2.single line Unix shell stype comment (#) 3.multi line c style comment (/*/) single or multi line comment comes to the end of the line or come first to the current block of php code.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 Create/Retrieve a Cookie. The following example creates a cookie named "user" with the value "John Doe". The cookie will expire after 30 days (86400 * 30). The "/" means that the cookie is available in entire website (otherwise, select the directory you prefer). We then retrieve the value of the cookie "user" (using the global variable ... Instagram Aug 1, 2023 · PHP-GTK related documentation is hosted on the PHP-GTK website. Documentation of PEAR and the various packages can be found on a separate server. You can still read a copy of the original PHP/FI 2.0 Manual on our site, which we only host for historical purposes. The same applies to the PHP 3 Manual . 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 You can also call the script from the command line after chmod'ing the file (ie: chmod 755 file.php). On your first line of the file, enter "#!/usr/bin/php" (or to wherever your php executable is located). If you want to suppress the PHP headers, use the line of "#!/usr/bin/php -q" for your path. up. down.
PHP Operators. Operators are used to perform operations on variables and values. PHP divides the operators in the following groups: Arithmetic operators. Assignment operators. Comparison operators. Increment/Decrement operators. Logical operators. String operators.. Jersey mikepercent27s closing time
default: code to be executed if n is different from all labels; } This is how it works: First we have a single expression n (most often a variable), that is evaluated once. The value of the expression is then compared with the values for each case in the structure. If there is a match, the block of code associated with that case is executed.Jun 17, 2022 · PHP is a server-side scripting language designed specifically for web development. It is open-source which means it is free to download and use. It is very simple to learn and use. The files have the extension “.php”. Rasmus Lerdorf inspired the first version of PHP and participated in the later versions. It is an interpreted language and ... 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.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.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 ...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 ...The interactive shell stores your history which can be accessed using the up and down keys. The history is saved in the ~/.php_history file. The CLI SAPI provides the php.ini settings cli.pager and cli.prompt. The cli.pager setting allows an external program (such as less) to act as a pager for the output instead of being displayed directly on ...Feb 6, 2023 · How to increase PHP memory_limit. To increase the PHP memory limit setting, edit your PHP.ini file. Increase the default value (example: Maximum amount of memory a script may consume = 128MB) of the PHP memory limit line in php.ini. memory_limit = 1024M. Alternatively, you can edit your .htaccess file (Not recommended. 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.Apr 24, 2023 · PHP is a server-side scripting language, which means that a server executes the instructions in a script. Then, the server provides data on request, channels the requests, and organizes the information in a database. When a web server receives a script, it will process the request and send output to a web browser in an HTML format. Aug 1, 2023 · PHP-GTK related documentation is hosted on the PHP-GTK website. Documentation of PEAR and the various packages can be found on a separate server. You can still read a copy of the original PHP/FI 2.0 Manual on our site, which we only host for historical purposes. The same applies to the PHP 3 Manual . This is an example PHP application, which is intentionally vulnerable to web attacks. It is intended to help you test Acunetix. It also helps you understand how developer errors and bad configuration may let someone break into your website. You can use it to test other tools and your manual hacking skills as well. Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures FunctionsPHP-GTK related documentation is hosted on the PHP-GTK website. Documentation of PEAR and the various packages can be found on a separate server. You can still read a copy of the original PHP/FI 2.0 Manual on our site, which we only host for historical purposes. The same applies to the PHP 3 Manual .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.This is an example PHP application, which is intentionally vulnerable to web attacks. It is intended to help you test Acunetix. It also helps you understand how developer errors and bad configuration may let someone break into your website. You can use it to test other tools and your manual hacking skills as well. The PHP concatenation operator (.) is used to combine two string values to create one string. .=. Concatenation assignment.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.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..