This document provides an introduction to PHP, describing its history, basic syntax, and programming operations. It explains PHP as a high-level, server-side scripting language used for web development and database management. The document also presents various operators, including arithmetic, assignment, comparison, increment/decrement, logical, and string operators, along with their functionalities.

1. Chapter two
Introduction to PHP
Compiled By: Fekadu E.
Email: fikeeshetu@gmail.com
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2. Out Line
 In this session we will see
 The definition of PHP
 Basic Syntax in PHP
 Programming Operation in PHP
 Variables in PHP
 The Goal of this session
 Understand the basic Syntax of PHP
 Understand the use of operator in PHP
 Understand declare, scope of Variables in PHP
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3. What is PHP?
 PHP is a popular high-level scripting language used by a range of organizations and
developers.
 Originally developed as a small Perl project by Rasmus Lerdorf in late 1995, PHP
was intended as a means to assist in developing his home page, and as such he named
it Personal Home Page (PHP) Tools.
 When Lerdorf was contracted to work for the University of Toronto to build a dial-
up system for students to access the Internet, he had no means of connecting Web
sites to databases. To solve this problem, the enterprising Lerdorf replaced his
Perl code with a C wrapper that added the capability to connect his Web pages to a
MySQL database.
 As his small project grew, he gave away his changes on the Internet as an Open
Source project and cordially received improvements from other programmers with
an interest in PHP.
 The language was later renamed to the current recursive acronym PHP: Hypertext
Preprocessor by Zeev Suraski and Andi Gutmans after they rewrote the parser in
1997.
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4. Introduction
 PHP is an acronym for "PHP: Hypertext Preprocessor“
 PHP is a server-side, open source scripting language
 PHP is cross platform
 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
 PHP provides a solid and well-defined programming language that includes support
for
 object-orientated programming,
 file handling,
 arithmetic, and more
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5. Common use of PHP
 PHP performs system functions, i.e. it can create, open, read, write,
and close from files on a system
 PHP allows to add, delete, modify elements within your database
 Access cookies variables and set cookies
 restrict users to access some pages of your website
 encrypt data
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6. Why I need PHP?
 PHP runs on different platforms (Windows, Linux, Unix, etc.)
 PHP is compatible with almost all servers used today like apache.
 PHP is FREE to download from the official PHP resource: www.php.net
 PHP is easy to learn and runs efficiently on the server side
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7. PHP Syntax
 A PHP script always
starts with <?php and
ends with ?>
 A PHP script can be placed anywhere in the document.
Syntax
PHP code should enclosed within:
<?php and ?> So that it is distinguished from HTML.
Hence, the PHP parser only parses code which is in between <?php and ?>
 PHP code can be embedded in HTML
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8. PHP Operators
 Operators are used to perform operations on variables and values.
 basically operators are divided in to the following group.
 Arithmetic operators
 Assignment operators
 Comparison operators
 Increment/Decrement operators
 Logical operators
 String operators
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9. PHP Arithmetic Operators
 The PHP arithmetic operators are used with numeric values to
perform common arithmetical operations, such as addition,
subtraction, multiplication etc.
Operator Name Example Result
+ Addition $x + $y Sum of $x and $y
- Subtraction $x - $y Difference of $x and $y
* Multiplication $x * $y Product of $x and $y
/ Division $x / $y Quotient of $x and $y
% Modulus $x % $y Remainder of $x divided by
$y
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10. PHP Assignment Operators
 The PHP assignment operators are used with numeric values to write a value to a
variable.
 The basic assignment operation in PHP is “=“.
Assignment Same as... Description
x = y x = y The left operand gets set to the value of the expression on
the right
x += y x = x + y Addition
x -= y x = x - y Subtraction
x *= y x = x * y Multiplication
x /= y x = x / y Division
x %= y x = x % y Modulus
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11. PHP Comparison Operators
 The PHP comparison operators are used to compare two values (number or string)
Operator Name Example Result
== Equal $x == $y Returns true if $x is equal to $y
=== Identical $x === $y Returns true if $x is equal to $y, and they
are of the same type
!= Not equal $x != $y Returns true if $x is not equal to $y
<> Not equal $x <> $y Returns true if $x is not equal to $y
!== Not identical $x !== $y Returns true if $x is not equal to $y, or they
are not of the same type
> Greater than $x > $y Returns true if $x is greater than $y
< Less than $x < $y Returns true if $x is less than $y
>= Greater than or
equal to
$x >= $y Returns true if $x is greater than or equal to
$y
<= Less than or equal
to
$x <= $y Returns true if $x is less than or equal to $y
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12. PHP Increment / Decrement Operators
 The PHP increment operators are used to increment a variable's value.
 The PHP decrement operators are used to decrement a variable's value.
Operator Name Description
++$x Pre-increment Increments $x by one, then returns $x
$x++ Post-
increment
Returns $x, then increments $x by one
--$x Pre-
decrement
Decrements $x by one, then returns $x
$x-- Post-
decrement
Returns $x, then decrements $x by one
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13. PHP Logical Operators
 The PHP logical operators are used to combine conditional statements.
Operator Name Example Result
and And $x and $y True if both $x and $y are true
or Or $x or $y True if either $x or $y is true
xor Xor $x xor $y True if either $x or $y is true,
but not both
&& And $x && $y True if both $x and $y are true
|| Or $x || $y True if either $x or $y is true
! Not !$x True if $x is not true
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14. PHP String Operators
 PHP has two operators that are specially designed for strings
Operator Name Example Result
. Concatenation $txt1 . $txt2 Concatenation of $txt1
and $txt2
.= Concatenation
assignment
$txt1 .= $txt2 Appends $txt2 to $txt1
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15. What is Variable?
 Variable is a symbol or name that stands for a value.
 Variables are used for storing values such as numeric values,
characters, character strings.
 Variable in PHP is case insensitive.
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16. Activity???
1. What is PHP?
2. What is open source?
3. List Type of Operation.
4. What is variable?
5. How declare variable in PHP?
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