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.
What is PHP
PHP stands for HyperText Preprocessor.
PHP is an interpreted language, i.e. there is no need for compilation.
PHP is a server side scripting language.
PHP is faster than other scripting language e.g. asp and jsp.
Common uses of PHP
PHP performs system functions, i.e. from files on a system it can create, open, read, write, and close them.
PHP can handle forms, i.e. gather data from files, save data to a file, through email you can send data, return data to the user.
You add, delete, modify elements within your database through PHP.
Access cookies variables and set cookies.
Using PHP, you can restrict users to access some pages of your website.
It can encrypt data.
Web Development
PHP is widely used in web development now a days. Dynamic websites can be easily developed by PHP. But you must have the basic the knowledge of following technologies for web development as well.
HTML
CSS
JavaScript
AJAX
XML and JSON
JQuery
Characteristics of PHP
Five important characteristics make PHP's practical nature possible −
Simplicity
Efficiency
Security
Flexibility
Familiarity
PHP Features
There are given many features of PHP.
Performance: Script written in PHP executes much faster then those scripts written in other languages such as JSP & ASP.
Open Source Software: PHP source code is free available on the web, you can developed all the version of PHP according to your requirement without paying any cost.
Platform Independent: PHP are available for WINDOWS, MAC, LINUX & UNIX operating system. A PHP application developed in one OS can be easily executed in other OS also.
Compatibility: PHP is compatible with almost all local servers used today like Apache, IIS etc.
Embedded: PHP code can be easily embedded within HTML tags and script.
Install PHP
To install PHP, we will suggest you to install AMP (Apache, MySQL, PHP) software stack. It is available for all operating systems. There are many AMP options available in the market that are given below:
WAMP for Windows
LAMP for Linux
MAMP for Mac
SAMP for Solaris
FAMP for FreeBSD
XAMPP (Cross, Apache, MySQL, PHP, Perl) for Cross Platform: It includes some other components too such as FileZilla, OpenSSL, Webalizer, Mercury Mail etc.
If you are on Windows and don't want Perl and other features of XAMPP, you should go for WAMP. In a similar way, you may use LAMP for Linux and MAMP for Macintosh.
PHP 5 Syntax
A PHP script can be placed anywhere in the document.
PHP - Variable Types
PHP Variables
A variable in PHP is a name of memory location that holds data. A variable is a temporary storage that is used to store data temporarily.
In PHP, a variable is declared using $ sign followed by variable name.
Syntax of declaring a variable in PHP is given below:
$variablename=value;
PHP has a total of eight data types which we use to construct our variables −
Integers − are whole numbers, without a decimal point, like 4195.
Doubles − are floating-point numbers, like 3.14159 or 49.1.
Booleans − have only two possible values either true or false.
NULL − is a special type that only has one value: NULL.
Strings − are sequences of characters, like 'PHP supports string operations.'
Arrays − are named and indexed collections of other values.
Objects − are instances of programmer-defined classes, which can package up both other kinds of values and functions that are specific to the class.
Resources − are special variables that hold references to resources external to PHP (such as database connections).
