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.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 ...Php login script is used to provide the authentication for our web pages. the Script executes after submitting the user login button. Login Page Login page should be as follows and works based on session.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.Example Get your own PHP Server. When the user fills out the form above and clicks the submit button, the form data is sent for processing to a PHP file named "welcome.php". The form data is sent with the HTTP POST method. To display the submitted data you could simply echo all the variables. The "welcome.php" looks like this: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 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 ».Parameters format. Format accepted by DateTimeInterface::format().. Note: date() will always generate 000000 as microseconds since it takes an int parameter, whereas DateTime::format() does support microseconds if DateTime was created with microseconds.Validate Form Data With PHP. The first thing we will do is to pass all variables through PHP's htmlspecialchars () function. When we use the htmlspecialchars () function; then if a user tries to submit the following in a text field: - this would not be executed, because it would be saved as HTML escaped code, like this:PHP: 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 ...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. 8.2.10 · Changelog · Upgrading.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!"Feb 13, 2012 · Encryption in PHP is actually simple (we're going to use openssl_encrypt () and openssl_decrypt () once you have made some decisions about how to encrypt your information. Consult openssl_get_cipher_methods () for a list of the methods supported on your system. The best choice is AES in CTR mode: 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.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 /..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.This package was approved as a trusted package on 30 Aug 2023. Description. PHP is an HTML-embedded scripting language. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly.Validate Form Data With PHP. The first thing we will do is to pass all variables through PHP's htmlspecialchars () function. When we use the htmlspecialchars () function; then if a user tries to submit the following in a text field: - this would not be executed, because it would be saved as HTML escaped code, like this: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!"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.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 1:25strpos () - Search For a Text Within a String. The PHP strpos () function searches for a specific text within a string. If a match is found, the function returns the character position of the first match. If no match is found, it will return FALSE.PHP operators for beginners and professionals with examples, php file, php session, php date, php array, php form, functions, time, xml, ajax, php mysql, regex ...11 years ago. The NOT or complement operator ( ~ ) and negative binary numbers can be confusing. ~2 = -3 because you use the formula ~x = -x - 1 The bitwise complement of a decimal number is the negation of the number minus 1. NOTE: just using 4 bits here for the examples below but in reality PHP uses 32 bits.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.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;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 ...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 ...Example Get your own PHP Server. When the user fills out the form above and clicks the submit button, the form data is sent for processing to a PHP file named "welcome.php". The form data is sent with the HTTP POST method. To display the submitted data you could simply echo all the variables. The "welcome.php" looks like this:In PHP, the array () function is used to create an array: array (); In PHP, there are three types of arrays: Indexed arrays - Arrays with a numeric index. Associative arrays - Arrays with named keys. Multidimensional arrays - Arrays containing one or more arrays.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.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.In PHP, the array () function is used to create an array: array (); In PHP, there are three types of arrays: Indexed arrays - Arrays with a numeric index. Associative arrays - Arrays with named keys. Multidimensional arrays - Arrays containing one or more arrays.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 by8.1. 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.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 login script is used to provide the authentication for our web pages. the Script executes after submitting the user login button. Login Page Login page should be as follows and works based on session.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.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!"worth reading for people learning about php and programming: (adding extras <?php ?> to get highlighted code) about the following example in this page manual: Example#1 Logical operators illustratedPHP 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" 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.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.Select and Filter Data From a MySQL Database. The WHERE clause is used to filter records. The WHERE clause is used to extract only those records that fulfill a specified condition. SELECT column_name (s) FROM table_name WHERE column_name operator value. To learn more about SQL, please visit our SQL tutorial.Feb 13, 2012 · Encryption in PHP is actually simple (we're going to use openssl_encrypt () and openssl_decrypt () once you have made some decisions about how to encrypt your information. Consult openssl_get_cipher_methods () for a list of the methods supported on your system. The best choice is AES in CTR mode: Parameters format. Format accepted by DateTimeInterface::format().. Note: date() will always generate 000000 as microseconds since it takes an int parameter, whereas DateTime::format() does support microseconds if DateTime was created with microseconds.PHP is a general-purpose scripting language geared towards web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by the PHP Group. Jan 14, 2021 · Check PHP Version by Running PHP Code. The simplest method to determine the PHP version running on your website is executing a PHP file that contains the following code: <?php echo 'PHP version: ' . phpversion(); Create the file using a text editor like gedit or Notepad, and upload it to your website’s document root directory. 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.Php login script is used to provide the authentication for our web pages. the Script executes after submitting the user login button. Login Page Login page should be as follows and works based on session.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.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.This package was approved as a trusted package on 30 Aug 2023. Description. PHP is an HTML-embedded scripting language. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly.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.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 · PECL. PHP Installer Tools on Windows. Recommended Configuration on Windows systems. Manual PHP Installation on Windows. Building from source. Command Line PHP on Microsoft Windows. Apache 2.x on Microsoft Windows. Troubleshooting PHP on Windows. Installation on Cloud Computing platforms. 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 ...worth reading for people learning about php and programming: (adding extras <?php ?> to get highlighted code) about the following example in this page manual: Example#1 Logical operators illustratedCommand line options; Option Long Option Description-a--interactive: Run PHP interactively. For more information, see the Interactive shell section.-b--bindpath: Bind Path for external FASTCGI Server mode (CGI only).Equal Operator == The comparison operator called Equal Operator is the double equal sign “==”. This operator accepts two inputs to compare and returns true value if both of the values are same (It compares only value of variable, not data types) and return a false value if both of the values are not same.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 parValidate Form Data With PHP. The first thing we will do is to pass all variables through PHP's htmlspecialchars () function. When we use the htmlspecialchars () function; then if a user tries to submit the following in a text field: - this would not be executed, because it would be saved as HTML escaped code, like this: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!"PHP User Defined Functions. Besides the built-in PHP functions, it is possible to create your own functions. A function is a block of statements that can be used repeatedly in a program. A function will not execute automatically when a page loads. A function will be executed by a call to the function.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 ...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.Also, you can increase PHP’s memory limit for specific websites. One method would be to place a php.ini file in the site’s webroot. You can even set the limit for specific scriptname.php. For example using ini_set(‘memory_limit’,’256MB’). How to increase PHP memory_limit. To increase the PHP memory limit setting, edit your PHP.ini file.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. 8.2.10 · Changelog · Upgrading.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 Version: 4+ PHP Changelog: PHP 7.2: The headers parameter also accepts an array PHP 5.4: Added header injection protection for the headers parameter. PHP 4.3.0: (Windows only) All custom headers (like From, Cc, Bcc and Date) are supported, and are not case-sensitive. PHP 4.2.3: The parameter parameter is disabled in safe mode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 /..Command line options; Option Long Option Description-a--interactive: Run PHP interactively. For more information, see the Interactive shell section.-b--bindpath: Bind Path for external FASTCGI Server mode (CGI only).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.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.Click on the URL button, Enter URL and Submit. This tool supports loading the PHP File to beautify. Click on the Upload button and select File. It beautify pure PHP framework file such as Laravel, CodeIgniter, YII, CakePHP, Symfony and many more one file at a time. PHP Source Code Beautifier Online works well on Windows, MAC, Linux, Chrome ...Belajar PHP Dasar Pengenalan Dan Kegunaan PHP. Selamat datang di tutorial PHP dasar Belajar PHP Part 1 : Pengenalan PHP di malasngoding.com. anda yang sudah mulai memasuki tutorial dasar php ini di asumsikan untuk mempelajari tentang HTML dan CSS dasar terlebih dahulu sebelum melompat ke tutorial PHP. untuk tutorial HTML dan CSS dasar nya ...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.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.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 byHere'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;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 ...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.Example Get your own PHP Server. When the user fills out the form above and clicks the submit button, the form data is sent for processing to a PHP file named "welcome.php". The form data is sent with the HTTP POST method. To display the submitted data you could simply echo all the variables. The "welcome.php" looks like this:W3Schools Spaces is a website-building tool that enables you to create and share your own website, as well as develop and host your PHP applications. You can change the website's look and how it works by editing the code right in your web browser. It's easy to use and doesn't require any setup
PHP User Defined Functions. Besides the built-in PHP functions, it is possible to create your own functions. A function is a block of statements that can be used repeatedly in a program. A function will not execute automatically when a page loads. A function will be executed by a call to the function.. Pottery place warehouse and metal art photos
The MySQLi Extension Function Summary mysqli — The mysqli class mysqli::$affected_rows — Gets the number of affected rows in a previous MySQL operation mysqli::autocommit — Turns on or off auto-committing database modifications mysqli::begin_transaction — Starts a transaction Feb 13, 2012 · Encryption in PHP is actually simple (we're going to use openssl_encrypt () and openssl_decrypt () once you have made some decisions about how to encrypt your information. Consult openssl_get_cipher_methods () for a list of the methods supported on your system. The best choice is AES in CTR mode: Select and Filter Data From a MySQL Database. The WHERE clause is used to filter records. The WHERE clause is used to extract only those records that fulfill a specified condition. SELECT column_name (s) FROM table_name WHERE column_name operator value. To learn more about SQL, please visit our SQL tutorial.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 ...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.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.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 ...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 ...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 ...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.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.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.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" 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.The MySQLi Extension Function Summary mysqli — The mysqli class mysqli::$affected_rows — Gets the number of affected rows in a previous MySQL operation mysqli::autocommit — Turns on or off auto-committing database modifications mysqli::begin_transaction — Starts a transaction I am working on an a PHP web application and i need to perform some network operations in the request like fetching someone from remote server based on user's request. Is it possible to simulatePHP 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 ...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..