PHP AND MYSQL BY EXAMPLE PDF

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PHP and MySQL by example / Ellie Quigley with Marko Gargenta. PHP and MySQL Programming” from the PDF version of that first draft. PHP and MySQL by Example - Ebook download as PDF File .pdf), Text File .txt) or read book online. dynamic Web site: PHP and MySQL. When we are . Following tradition, we will begin coding with a "hello world" example. Fire up .. and PDF files. Our ability.


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Lecture Notes in PHP and mySQL - Sample. PHP Tutorial 1 – Introduction to PHP . The Client is your local computer, while the Server is the remote computer. O'Reilly Media, Inc. Learning PHP, MySQL, JavaScript, and CSS, the image of sugar gliders, .. Answering a question by citing this book and quoting example. writing Web-based applications with PHP and MySQL. If you decide to go For example, in this book, you will not find a discussion of PHP's LDAP functions.

Pluralization defines the rules required between distinct languages to interoperate strings containing numbers and counters. For instance, in English when you have only one item, it is singular, and anything different from that is called plural; plural in this language is indicated by adding an S after some words, and sometimes changes parts of it.

In other languages, such as Russian or Serbian, there are two plural forms in addition to the singular - you may even find languages with a total of four, five or six forms, such as Slovenian, Irish or Arabic.

This way is, however, hardly recommended for serious projects, as it poses some maintenance issues along the road - some might appear in the very beginning, such as pluralization. The most classic way and often taken as reference for i18n and l10n is a Unix tool called gettext.

It dates back to and is still a complete implementation for translating software. It is easy enough to get running, while still sporting powerful supporting tools. It is about Gettext we will be talking here.

Also, to help you not get messy over the command-line, we will be presenting a great GUI application that can be used to easily update your l10n source Other tools There are common libraries used that support Gettext and other implementations of i18n. Some of them may seem easier to install or sport additional features or i18n file formats. It uses array formats for message. Does not provide a message extractor, but does provide advanced message formatting via the intl extension including pluralized messages.

Can be useful if you need to integrate your translation files into other parts of the system, like a JavaScript interface. Implements a caching layer to save you from reading the filesystem every time. It also includes view helpers, and locale-aware input filters and validators. However, it has no message extractor. Other frameworks also include i18n modules, but those are not available outside of their codebases: Laravel supports basic array files, has no automatic extractor but includes a lang helper for template files.

Yii supports array, Gettext, and database-based translation, and includes a messages extractor. It is backed by the Intl extension, available since PHP 5. If you decide to go for one of the libraries that provide no extractors, you may want to use the gettext formats, so you can use the original gettext toolchain including Poedit as described in the rest of the chapter.

Gettext Installation You might need to install Gettext and the related PHP library by using your package manager, like apt-get or yum. Here we will also be using Poedit to create translation files. Structure Types of files There are three files you usually deal with while working with gettext. Domains There are some cases, in big projects, where you might need to separate translations when the same words convey different meaning given a context.

In those cases, you split them into different domains. The pages were text based, simple, and static. Every time the user reloaded a page in his or her browser, it looked exactly the same. It consisted of HTML text, images, and links. It was not the complex commercial Web we know today where you can do anything from online shopping, to trading stocks, booking vacations, or finding a mate.

As the Web grew and became a virtual shopping mall, competitors needed Web sites that would lure in potential downloaders and traders with an interactive and exciting experience, quick response time, and on-the-fly feedback. They needed dynamic Web sites. Dynamic Web Sites A dynamic Web site is one with content that is regenerated every time a user visits or reloads the site. Google and Yahoo! The resulting page is created on the fly, customized just for you, based on your request.

Farms of powerful computers all over the world are constantly taking such requests and processing them. In the early days of the Web, processing was done through the Common Gateway Interface, called CGI, a server-side technology that allowed Web developers to create dynamic sites.

Most CGI scripts were written in Perl. A browser would send information from an HTML Web page, such as information from a fillout form, to the server for processing. The server then would create a gateway to an external program called a CGI script or helper program. Although any programming language could be used, the most. The Perl script would then parse the data, generate HTML based on certain conditions, send an e-mail, open a file or database, and send information through the gateway back to the server, where it then was relayed onto the browser.

See the top portion of Figure 1. Figure 1. The process of creating dynamic Web sites. A PHP script can be embedded right in the Web page. It can generate HTML and images on the fly, retrieve up-to-date information from a file or database, encrypt data, remember user preferences, and so on. It executes PHP instructions and inserts the results right back into the Web page before the server sends the page back to the browser, thus making the page truly dynamic.

See the bottom portion of Figure 1. Web sites often handle huge amounts of information. A database management system is essential for storing, retrieving, and updating that information. This book will show you how that marriage works. What Is Open Source? What does that mean? In the beginning Berners-Lee envisioned making information freely accessible to everyone.

See http: The Open Source movement is designed to make software source code freely available with limited restrictions. The basic idea behind open source is very simple: When programmers can read, redistribute, and modify the source code for a piece of software, the software evolves.

People improve it, people adapt it, people fix bugs. And this can happen at a speed that, if one is used to the slow pace of conventional software development, seems astonishing. For the complete discussion, see http: Simply stated, you can download and use these applications without a credit card or a free trial period.

So what is PHP? PHP is a simple, fast, portable scripting language well suited for development of database-enabled Web sites. It was developed in and is currently powering tens of millions of Web sites worldwide.

PHP was very Perl-like in sytnax, but whereas Perl is an all-purpose, jack-of-all-trades scripting language, PHP was designed specifically to master the Web. PHP made processing forms easier by providing automatic interpretation of form variables. It allowed for interaction with databases. It enabled users to create simple dynamic Web sites. Due to the popularity of this new release, Lerdorf was soon joined by a core group of developers, who continued to provide improvements and enhancements to the new language.

Zeev Suraski and Andi Gutmans, two students attending Technion-Israel Institute of Technology, needed a language for their university e-commerce project.

Dissatisfied with its limitations and bugs, they put their project aside, and rewrote PHP almost from scratch. PHP 3. The new language supported add-on modules and had a much more consistent syntax. At this time, the meaning of the acronym changed as well. Hypertext Preprocessor. By May , PHP 4 was released. The core of PHP 4 was entirely rewritten to improve the performance of complex Web applications and improve modularity of the platform.

Because of their internationally recognized authority, Suraski and Gutmans founded Zend Technologies, the PHP company, and their contributions to PHP have been a major reason for its explosive worldwide growth.

See www. Zeev and Andrew Version 4 offered an open Application Programming Interface API , allowing other programmers to write modules for PHP, modules that would extend its functionality, modules that allowed PHP 4 to support most of the available databases and Web servers available.

With this release, PHP became a serious programming language and platform for developing and deploying complex Web applications. The latest incarnation of PHP was released in July PHP 5 added a whole new object-oriented model to the language. Most of the functionality is backward compatible, allowing programs written in older versions to continue working.

This Web site is also an excellent up-to-date resource for PHP documentation. You can find a particular function, for example, by typing the search string into the top right corner of the page, and the result returned will be very close to what you were looking for, including links to other functions that perform a similar task.

Most of. The PHP home page. Today many organizations face the double threat of increasing volumes of data and transactions coinciding with a need to reduce spending. Many such organizations are migrating to open source database management systems to keep costs down and minimize change to their existing systems.

Australia, to provide fast access to stored data with low memory requirements. The MySQL home page. This is handled by a database management system such as MySQL where the data is stored in tables rather than in a flat file. It also supports SQL, the structured query language, a standardized language used by most modern databases for working with data and administering the database.

MySQL software is open source. As discussed earlier in this chapter, open source means that it is possible for anyone to download MySQL from the Internet, and use and modify the software without paying anything.

If you need to use MySQL code in a commercial application, you can download a commercially licensed version. MySQL Server was originally developed to handle large databases much faster than existing solutions and has been successfully used in highly demanding production environments for several years. MySQL serves as a back end for all kinds of information such as e-mail, Web images and content, games, log files, and so on.

The server can be embedded in applications such as cell phones, electronic devices, public kiosks, and more. PHP, a simple and powerful scripting language, and MySQL, a solid and reliable database server, make a perfect marriage between two modern technologies for building databasedriven, dynamic Web sites. MySQL, a highly optimized database server, provides the response time and throughput to meet the most demanding applications.

Problems encountered by other programmers have been solved and packaged into a library of routines, made available to the PHP community. The official PHP Web site at http: Extensibility PHP and MySQL are both extensible, meaning that developers around the world are contributing add-on modules to extend the functionality and power of the languages to stay current with the growing market needs and standards of the day.

Source code is the code that a program consists of before the program is compiled; that is, the original building instructions of a program. Because both applications run on almost any platform, you also have a wide range of hardware choices lowering the total cost of ownership.

With so many qualified PHP developers sharing information on the Web, and excellent online documentation, you can get the most up-to-date, reliable information without paying for it. If well written, you can simply copy the code from one server to another and expect the same results, perhaps with some minor adjustments. If you run into a problem, you can usually very quickly find support on the Web, where your problem can be posted, identified, and resolved by other users and developers sharing your problem.

Developers worldwide are constantly finding and resolving bugs and security holes, while working to keep these languages up-to-date and optimized. Most of the PHP constructs are similar to other languages, specifically Perl, making it familiar to most developers. Chapter Summary 1.

We will learn how to create and execute simple PHP scripts both from the browser and at the command line. We will talk about built-in functions and how to use them by viewing the PHP documentation Web site.

Figure 2. The life cycle of a typical Web page. The Steps Figure 2. We will explain each of steps by the number shown in the diagram. Everything between these two tags is interpreted by the PHP module also called interpreter and converted to regular text and HTML before being sent back to the requesting browser.

Consider the following simple PHP instruction consisting of an echo statement containing the string "Hello, world. What the PHP interpreter gets: Normally the extension is. This server accepts. From the Apache httpd. Each statement must be terminated with a semicolon with an exception if it is the last line of the script. PHP will produce an error message if you omit the semicolon, similar to this: Parse error: Table 2. Additional PHP Tags. To use short tags, you may have to change a setting in the PHP initialialization file, called php.

When you find the php. From the php. Using short tags should be avoided when developing applications or ; libraries that are meant for redistribution, or deployment on PHP ; servers which are not under your control, because short tags may not ; be supported on the target server. For portable, redistributable code, ; be sure not to use short tags.

For Apache, for example, the file is called httpd. The Web server will send the resulting page. PHP and the Web page. To see the source code received by the browser.

PHP tags will be removed. If there is output. HTML tags will be left alone. Any other text in the file is left as is. Before sending the page to the browser. Example 2. If you need to format the output. If you need a quote to be printed literally. These constructs are quite simple and do not do any fancy formatting see Example 2.

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Output of the PHP script in the browser. The quotes must be matched: To print more than one string with print. All strings must be enclosed in a pair of either single or double quotes. Print displays a string. Echo is like print but allows you to print more than one string by separating each string with a comma. PHP provides a number of functions. Parentheses are not required around the string. We have devoted a whole chapter to strings Chapter 6.

To join two strings together. Notice in Example 2. PHP is a programming language that consists of data and instructions and procedures that tell the computer what operations to perform on the data.

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If you are running on a UNIX system. See the error message in its output in Figure 2. HTML is called a markup language. To turn on execute permission for the script. If running locally. Ask your ISP for the correct method for uploading your file. See Figures 2. Viewing the source code of the page that you opened in your Web browser. Whitespace refers to spaces. PHP is called a free form language. Whitespace is used to delimit words and does not have other significance.

Both of the following PHP statements are correct: Note the characters preceded by a backslash and enclosed in quotes. In Chapter 6.

Any number of blank spaces are allowed between symbols and words. Certainly a clean style makes it easier to read as well as debug programs.

The style PHP uses comes from other languages such as C. The entire script could be written on one clean line see Figure 2. PHP comments can be written on a single line or cover multiple lines.

Output from Example 2. The first PHP script in Example 2. Comments are plain English text inserted within a script to explain what is going on. The style you use depends on how much you want to say. Comments You may write a very clever PHP script this afternoon. If the user views the source file in his or her browser. If you pass the script on to someone else. These comments are visible by viewing the source of the page.

Comments are ignored by the PHP interpreter. They are extremely important when working with a team of people to help communicate your intentions. Marko Gargenta Date: Another comment here? Using PHP Functions A big part of any programming language is the set of functions that are built into the language or packaged in special libraries. HTML comments are in italics. In Chapter 9. The PHP Web page for a complete list of built-in functions. All comments are invisible in the page.

Viewing the source. PHP comments are not visible. If you wanted to save the return value. Although it is customary to see function names in lowercase. We discuss variables in Chapter 4. You can send a value or values to a function and the function can send back a result. For a simple example. You just have to know what it is supposed to do. So what is a function?

A function is an independent piece of program code that is created to make your life easier. For example. The values you send to the function are called arguments. What the function sends back is called the return value. Different functions have different numbers of arguments and some have none at all. You can send data to it. We discuss functions in more detail in Chapter 9. You must know what it does.

How to get documentation for a specific PHP built-in function. This function is built into the PHP language. Source page—what our browser gets after PHP processing. The output of the PHP date function in the Web browser. On some operating systems. Each version brought changes to the language. Review To review once again the life cycle of a PHP file.

For more information on the date function. PHP comes preloaded. See installation instructions in Appendix E of this book. To execute this script from the command line. For Windows users. Consider that everything you learn to do in PHP for the Web can be executed as a command-line script as well. Command-line applications are scripts that run from the command-line prompt and work well with plain text and files.

First we create the script. Click Start. This is PHP Version 5. Testing your script at the command line is often helpful for testing and debugging.

See Figure 2. To find what version of PHP you are currently running see Figure 2. For Macintosh users. The -f switch tells PHP to treat the file as a script. You can press Control-C to exit.

Using PHP interactively. You will get output similar to that shown in Figure 2. Be sure to start your interactive session with the opening PHP tag as shown in Figure 2. Give the php executable the -f switch and the name of your script. PHP at the command line. Type this at the prompt: On the command line. This is helpful when you want to check syntax before actually writing a script.

For the most part. Finding the path to your php. This is typically where the Web server will look for the php. You can use the phpinfo function in a script to find the path to your php. The directory from which the PHP script was called. You might have several copies of the php. Occasionally you might want to change a setting. Common settings you might want to change are: You might have to restart your Web server once you have changed the php.

Because the php. The php. Look at the sixth line in Figure 2. By default.. For several security-oriented considerations that should be taken. This file controls many aspects of PHP's behavior. This is the default settings file for new PHP installations About this file. This is an excerpt from the php.. The syntax of the file is extremely simple.. Section headers e. Under Windows. Directives are specified using the following syntax: Whitespace and Lines.

PHP installs itself with a configuration suitable for In order for PHP to. PHP looks for it in the current. Each section references the chapter and page number where a particular construct is described in detail. Chapter 3. Chapter Summary 2. Chapter 2 Lab 1. The next chapter also serves as quick reference after learning PHP. Because most of the programming concepts are very similar between languages.

That is the path to the php. Operating income: Income after taxes: You do not need to do any calculations at this point. View the output in your browser. The PHP portion of the program will print the incoming costs for a book store. What are some of the arguments you can pass to the phpinfo function? See the PHP manual. Echo prints comma-separated strings and does not return anything.

Quick Reference 3. PHP Quick Start 3. Quick Start. Table 3. A Note to Programmers If you have had previous programming experience in another language. Single quotes: Variables outside the function are not available inside the function.

A function might or might not return a value. Data can be passed to the function via arguments. Any valid PHP code can make up the definition block of a function. Instantiating a class: To close a file: To write to a file: To read from a file: A Note to Nonprogrammers If you are not familiar with programming.

In Chapter 4. You also learn how to define and display variables. PHP Syntax and Constructs 3. Chapter Summary This chapter was provided for programmers who need a quick peek at what PHP looks like. You learn how to work with different types of numbers. Data types specify what kind of data. Basic data types are the simplest building blocks of a program. Chapter 4. Arrays and objects hold multiple values.

Data Types A program can do many things. To do anything. See Figure 4. PHP supports a number of fundamental basic data types. Scalars hold one value. PHP also supports composite data types. They are called scalars and can be assigned a single literal value such as a number.

The composite data types are discussed in Chapter 8. Figure 4. The Building Blocks: Data Types. Composite data types represent a collection of data. Integers can be expressed in decimal base Example 4. The different types of data are commonly stored in variables.

Variables hold values that can change throughout the program.

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Numeric Literals PHP supports both integers and floating-point numbers. PHP supports four core data types: See Example 4. PHP numbers can be very large the size depends on your platform. They must contain a decimal point or an exponent specifier. String literals are a row of characters enclosed in either double or single quotes.

Here documents. Strings are called constants or literals. Escape sequences cause a character to behave in a certain way. The string value "hello" is called a string constant or literal. Single quotes can hide double quotes.

If a string of characters is enclosed in single quotes. String Literals and Quoting We introduce strings in this chapter but Chapter 6. Strings can contain escape sequences a single character preceded with a backslash. To change a string requires replacing it with another string. If the string starts with a single quote.

If a string is enclosed in double quotes.

We can say the single quotes are the democratic quotes: All characters are treated equally. Double quotes do not treat all characters equally.

If a number is enclosed in quotes. Output from Example 4. The backslash is also used for quoting a single character so that it will not be interpreted. Rules for a Here Document: The entire block of text is treated as though it is surrounded by double quotes. Single and double quotes.

Shell scripts.. Here document output. To display the escape sequences in your browser. Escape Sequences Escape sequences consist of a backslash followed by a single character. Table 4. When enclosed in double quotes. When using numeric comparison and equality operators. They are used to test whether a condition is true or false. An uninitialized variable contains the value NULL. Escape sequences at the command line. You can think of the values as yes or no.

It is a type of NULL. A variable can be assigned the value NULL. True and false. Boolean Literals Boolean literals introduced in PHP 4 are logical values that have only one of two values.

Resources are created and used by special functions. File and database resources are defined by the PHP interpreter and are only accessible by functions provided by the interpreter see Chapter PHP data types. The gettype Function The gettype built-in function returns a string to identify the data type of its argument.

The argument might be a variable. Resource A resource is a special variable. You can use the gettype function to check whether or not a variable has been defined because if there is no value associated with the variable.

Strings returned from the gettype function include the following: Variables are containers that hold data such as numbers and strings. In PHP programs there are three types of variables: They are data items that represent a memory storage location in the computer. PHP variables can be assigned different types of data. Variables 4. Definition and Assignment Variables are fundamental to all programming languages.

Variable names are case sensitive. You can declare multiple variables on the same line by separating each declaration with a semicolon. PHP variables can be declared in a script. Declaring and Initializing Variables Variables are normally declared before they are used.

With PHP you would simply say: You can assign a value to the variable or initialize a variable when you declare it. The first letter must be a letter or an underscore see Table 4.

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In fact. Valid Names Variable names consist of any number of letters an underscore counts as a letter and digits. With or without quotes. Backquotes and Windows. Backquotes and UNIX. There can be no space between the question mark and the equal sign. The only essential difference between echo and print is that echo allows multiple.

These language constructs can be used interchangeably.

Three variables are declared: Use caution: All of the following formats are acceptable: If enclosed in single quotes. For portable. Using short tags should be avoided when developing applications or. Displaying Variables The print and echo Constructs So far. The same strings are enclosed in double quotes: Like all other characters enclosed within single quotes. Neither require parentheses around their arguments because technically they are not functions.

The following strings are enclosed in single quotes: To print formatted strings. If a variable is enclosed in double quotes. With single quotes. Variables and Mixed Data Types Remember. Using shortcut tags. PHP will convert the type to the proper data type see Table 4. In Example 4. HTML source page viewed in the browser. You can assign a string to a variable and later assign a numeric value.

In each successive statement. The output from Example 4. Mixing data types. The gettype built-in function is used to display the data types after PHP has converted the data to the correct type. The dot is an operator because it operates on the expression on either side of it each called an operand.

PHP converts numeric values to strings. In expressions involving numeric and string values with the dot operator. Concatenation and Variables To concatenate variables and strings together on the same line.

Type Casting Like C and Java. PHP provides a method to force the conversion of one type of value to another using the cast operator see Chapter 5. A reference is when one variable is an alias or pointer to another variable. To assign by reference. This might be useful in speeding things up when using large arrays and objects. References Another way to assign a value to a variable is to create a reference PHP 4. They reference the same data. Changing one variable automatically changes the other.

By using two dollar signs. Output is shown in Figure 4. Curly braces are used to ensure that the PHP parser will evaluate the dollar signs properly. Consider the following example: One important thing to note is that only named variables can be assigned by reference. Variable Variables Dynamic Variables A variable variable is also called a dynamic variable. It is a variable whose name is stored in another variable. Dynamic variables. If you omit them.

Local Variables Variables created within a function are not available to the rest of the script. Global and Environment Variables Superglobal variables see Table 4. See Chapter 9. If you have the same name for a variable within a function as in the main program.

Managing Variables You might want to find out if a variable has been declared. PHP has specific rules to control the visibility of variables. For the most part all PHP variables have a single scope. A local variable is one that exists only within a function. PHP provides a number of functions see Table 4.

Scope is important because it prevents important variables from being accidentally modified in some other part of the program and thus changing the way the program behaves. Most of the variables we create will be visible in the script or function in which they are declared. They are local to the function and disappear go out of scope when the function exits. Scope of Variables Scope refers to where a variable is available within a script. A global variable is available anywhere in the script other than from within functions.

See Examples Format bool isset variable. If you want to see if a variable has been set to NULL. If the variable has been set to NULL or has no value. To ensure that a variable has an initial value. Is the variable set?

The empty Function The empty function returns true if a variable does not exist. Setting a default value. Format boolean empty variable. The unset Function The unset function technically a language construct unsets or destroys a given variable. It can take a varied number of arguments and behaves a little differently within functions see Chapter 9. Is the variable empty? As of PHP 4. Destroying variables.

As we mentioned in the introduction to this book, PHP was designed as a Web-based programming language to create dynamic Web content, to gather and manipulate information submitted by HTML forms. For now, because we are talking about variables, we will examine a simple form and how PHP collects and stores the form information in variables.

The PHP initialization file, called php. Older versions of PHP prior to 4. If using PHP 5, you will have to turn this feature on before PHP can directly assign form input to simple global variables, or the data must be extracted programatically. We discuss both ways to do this in the following section. The next excerpt is taken from the PHP 5 php. After extracting this information, PHP will create simple variables corresponding to the form data as shown in Example 4.

For example, consider this HTML input type for two text fields: After the user fills out the form see Figure 4. The browser just assumes that is the method you are using. It is the method used when doing searches or handling static pages and GET query strings are limited in size see Figure 4. When PHP gets the form input from the server, it takes care of decoding the query string or message body and assigning the respective input values to PHP variables as shown in Example 4.

The HTML form has been filled out by a user. Output from the PHP script in Example 4. The input data is appended to the URL after the?. Extracting the Data by Request In the previous example, we used the default GET method to send form input to the server.

This method sends the form input as a message body in the HTTP header to the server and does not append the data to the URL in the browser.

Even though the input data is sent using a different method, it is received in the same URL-encoded format. Please enter your phone: After PHP processes the input data from the form. Some are defined in the php.

These variables describe the environment, server, browser, version number, configuration file, and so on. See the full list of predefined variables at http: PHP variables partial output from the phpinfo function. There many more predefined variables; which ones are set depends on your PHP configuration. The function phpinfo can be used to retrieve built-in variables that have been set.

PHP not only provides its own predefined constants but lets you create your own. Using constants makes it easy to write and maintain your programs.

What Is a Constant? Unlike variables, a constant is a value that, once set, cannot be changed or unset during the execution of your script. An example of a constant is the value of pi or the version of PHP you are using.

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Once defined, those values are fixed. You can define constants at the top of your program or in another file that can be included in your script. Later if a constant value needs to be modified, once you change its value in the program, then when the program is executed, the new value will be reflected wherever the constant is used throughout the program, thus facilitating program maintenance.

Creating Constants with the define Function PHP constants are defined as words, and by convention, capitalized. Like variables, they are case sensitive and consist of uppercase and lowercase letters, numbers, and the underscore.

Like variables, they cannot start with a number. Unlike variables, constants are not preceded by a dollar sign and are not interpreted when placed within quotes. Constants are global in scope, meaning they are available for use anywhere in a PHP script.

The only way that you can create a constant is with he PHP built-in define function. Only a single, scalar value can be assigned to a constant, including strings, integers, floats, and booleans. The define function creates a named constant. The first argument is the name of the constant and the second argument is the value that will be assigned to it.

Constants are normally case sensitive, but you can use an optional third argument of TRUE to turn off case sensitivity. User-defined constants. The defined function checks whether a constant has been set. The constant Function The constant function returns that value of a constant.

There are five predefined constants called magic constants see Table 4. These are constants that change depending on how they are used in a program. They cannot be enclosed in quotes and are not case sensitive. The name of the contant is enclosed in two underscores on both sides. Magic Constants.

PHP has several special built-in constants described in Table 4. Built-In Constants. The script in Example 4.Look at the precedence table Table 5. What It Does Run interactively. See Table 6. The expression simplified means. If the third argument is specified.

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