Aug 1, 2023 · The simplest way to specify a string is to enclose it in single quotes (the character ' ). To specify a literal single quote, escape it with a backslash ( \ ). To specify a literal backslash, double it ( \\ ). All other instances of backslash will be treated as a literal backslash: this means that the other escape sequences you might be used to ... 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 ...Aug 1, 2023 · 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). Aug 1, 2023 · str_pad () can provide sufficient "zero padding" when using block ciphers and manual padding with openssl_encrypt () and similar. The example below will pad the 6 character text "Secret" with two \x00 characters and return 8 characters of data. Substitute your plain text and block size as needed. May 5, 2012 · 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. 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.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 ...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.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. 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 ...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: 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. 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. The W3Schools online code editor allows you to edit code and view the result in your browserAug 1, 2023 · However, PHP Manual is not listed "(" and ")" in precedence list. It looks like "(" and ")" has higher precedence as it should be. Note: If you write following code, you would need "()" to get expected value. The PHP concatenation operator (.) is used to combine two string values to create one string. .=. Concatenation assignment. PHP 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 ...A file with the PHP file extension is a PHP source code file that contains Hypertext Preprocessor code. They are often used as web page files that generate HTML from a PHP engine running on a web server. The HTML content that the PHP engine creates from the code is what's seen in the web browser. Since the web server is where the PHP code is ...Nov 12, 2010 · PHP Collective See more This question is in a collective: a subcommunity defined by tags with relevant content and experts. Featured on Meta I run 'php artisan migrate' command on window 8.1, laravel 7, xamp (php version 7.3.2) . I found some error, my all table did not migrate, how to fix [closed] Illuminate\Database\QueryException SQLSTATE [42S01]: Base table or view already exists: 1050 Table 'users' already exists. I have a CLI screenshot of the error: 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.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.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: I run 'php artisan migrate' command on window 8.1, laravel 7, xamp (php version 7.3.2) . I found some error, my all table did not migrate, how to fix [closed] Illuminate\Database\QueryException SQLSTATE [42S01]: Base table or view already exists: 1050 Table 'users' already exists. I have a CLI screenshot of the error: Aug 1, 2023 · The simplest way to specify a string is to enclose it in single quotes (the character ' ). To specify a literal single quote, escape it with a backslash ( \ ). To specify a literal backslash, double it ( \\ ). All other instances of backslash will be treated as a literal backslash: this means that the other escape sequences you might be used to ... 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.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 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 parJan 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. 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 class definitions begin with the keyword class, followed by a class name, followed by a pair of curly braces which enclose the definitions of the properties and methods belonging to the class. The class name can be any valid label, provided it is not a PHP reserved word. A valid class name starts with a letter or underscore, followed by ...Mar 15, 2022 · by Tali Smith. The fastest and easiest way to install PHP on Internet Information Services (IIS) is by using the Microsoft® Web Platform Installer (Web PI). Web PI completely automates setting up IIS, FastCGI, and the latest version of PHP from the php.net Web site. With Web PI, you can navigate to the "Web Platform" tab and select "PHP" under ... echo and print are more or less the same. They are both used to output data to the screen. The differences are small: echo has no return value while print has a return value of 1 so it can be used in expressions. echo can take multiple parameters (although such usage is rare) while print can take one argument. echo is marginally faster than print. Hi, I'm cfreak and I'm a PHP coder. Now you know me. I absolutely hate it. :-) (of course I don't really like PHP at all but it pays the bills so I do it)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. Dec 19, 2021 · 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. Zhejiang, Wade-Giles romanization Che-chiang, conventional Chekiang, sheng (province) of southeastern China. It is one of the smallest province-level political units of China, but it is also one of the most densely populated and affluent. A coastal province, it is bounded by the East China Sea to the east, by the provinces of Fujian to the ...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.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 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. 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.strpos () - 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. Basic class definitions begin with the keyword class, followed by a class name, followed by a pair of curly braces which enclose the definitions of the properties and methods belonging to the class. The class name can be any valid label, provided it is not a PHP reserved word. A valid class name starts with a letter or underscore, followed by ...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.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:Nov 12, 2010 · PHP Collective See more This question is in a collective: a subcommunity defined by tags with relevant content and experts. Featured on Meta The double arrow operator, =>, is used as an access mechanism for arrays. This means that what is on the left side of it will have a corresponding value of what is on the right side of it in array context. This can be used to set values of any acceptable type into a corresponding index of an array. The index can be associative (string based) or ...Aug 1, 2023 · 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 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. Jul 15, 2021 · Hi, friends. At the moment the script works only on Ubuntu 18.04. In the Inet there are a lot of tutorials how to install php 7.3-8.0 on Ubuntu 14.04/16.04. Installed as CGI binary. Installed as an Apache module. Persistent Database Connections. — Using PHP from the command line. DTrace Dynamic Tracing. Function Reference. Affecting PHP's Behaviour. Audio Formats Manipulation. Command Line Specific Extensions.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: 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.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.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.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 ...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. Aug 1, 2023 · It allows for conditional execution of code fragments. PHP features an structure that is similar to that of C: is evaluated to its Boolean value. If , PHP will execute , and if it evaluates to - it'll ignore it. More information about what values evaluate to 'Converting to boolean'. Often you'd want to have more than one statement to be ... 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.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.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 ...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, build date, and copyright information. Note: If there is more than one PHP version installed on the server, the php -v command shows the default command-line interface (CLI) version.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. Mar 20, 2013 · Easy Method is: Just copy the file cmd.exe from c:/windows/system32/ and paste it to C:\xampp\php\ and run it, when the cmd opens type " php -v " without quotes and hit enter... you will get your php version.. thank you 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 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 ...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.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 ...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 ...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. Grav 1.7.29 PHP 8.1 benchmark results: 2137.43 req/sec 🏆; PHP 8.1 is the undisputed winner with Grav, closely followed by PHP 8.0 and the rest. Being a relatively new CMS, it has a smaller market share than WordPress. Hence, it can drop support for older PHP versions quite quickly. That’s one of the most significant advantages of modern CMSs.Mar 20, 2013 · Easy Method is: Just copy the file cmd.exe from c:/windows/system32/ and paste it to C:\xampp\php\ and run it, when the cmd opens type " php -v " without quotes and hit enter... you will get your php version.. thank you It allows for conditional execution of code fragments. PHP features an structure that is similar to that of C: is evaluated to its Boolean value. If , PHP will execute , and if it evaluates to - it'll ignore it. More information about what values evaluate to 'Converting to boolean'. Often you'd want to have more than one statement to be ...PHP 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 ...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 ...ternary operator: The ternary operator (?:) is a conditional operator used to perform a simple comparison or check on a condition having simple statements. It decreases the length of the code performing conditional operations. The order of operation of this operator is from left to right.Jul 24, 2023 · A file with the PHP file extension is a PHP source code file that contains Hypertext Preprocessor code. They are often used as web page files that generate HTML from a PHP engine running on a web server. The HTML content that the PHP engine creates from the code is what's seen in the web browser. Since the web server is where the PHP code is ... 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.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.This is not what PHP references are. Instead, all PHP variables are actually references to an internal type called a zval. You cannot directly manipulate zvals in PHP, and nor can you make extra layers of indirection - every variable is a reference to a zval, and that's it. (See caveat: objects below.)Aug 1, 2023 · It allows for conditional execution of code fragments. PHP features an structure that is similar to that of C: is evaluated to its Boolean value. If , PHP will execute , and if it evaluates to - it'll ignore it. More information about what values evaluate to 'Converting to boolean'. Often you'd want to have more than one statement to be ... 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.Escape sequences. The backslash character has several uses. Firstly, if it is followed by a non-alphanumeric character, it takes away any special meaning that character may have. This use of backslash as an escape character applies both inside and outside character classes. For example, if you want to match a "*" character, you write "\*" in ...Mar 15, 2022 · by Tali Smith. The fastest and easiest way to install PHP on Internet Information Services (IIS) is by using the Microsoft® Web Platform Installer (Web PI). Web PI completely automates setting up IIS, FastCGI, and the latest version of PHP from the php.net Web site. With Web PI, you can navigate to the "Web Platform" tab and select "PHP" under ... 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.This is like an E_WARNING set by the programmer using the PHP function trigger_error() E_USER_NOTICE 1024; User-generated notice. This is like an E_NOTICE set by the programmer using the PHP function trigger_error() E_STRICT 2048; Run-time notices. PHP suggest changes to your code to help interoperability and compatibility of the code; E ...The PHP concatenation operator (.) is used to combine two string values to create one string. .=. Concatenation assignment.Aug 23, 2011 · Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions
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.. Denizbank doviz kurlari
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 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.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: 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 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 ...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 double arrow operator, =>, is used as an access mechanism for arrays. This means that what is on the left side of it will have a corresponding value of what is on the right side of it in array context. This can be used to set values of any acceptable type into a corresponding index of an array. The index can be associative (string based) or ...PHP is an open-source, interpreted, and object-oriented scripting language that can be executed at the server-side. PHP is well suited for web development. Therefore, it is used to develop web applications (an application that executes on the server and generates the dynamic page.). PHP was created by Rasmus Lerdorf in 1994 but appeared in the ...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.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.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.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.Aug 1, 2023 · It allows for conditional execution of code fragments. PHP features an structure that is similar to that of C: is evaluated to its Boolean value. If , PHP will execute , and if it evaluates to - it'll ignore it. More information about what values evaluate to 'Converting to boolean'. Often you'd want to have more than one statement to be ... It would appear that in php the increment in the left side of the assignment is processed prior to processing the right side of the assignment, whereas in C, neither increment occurs until after the assignment.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 ... .