PHP is a server-side scripting language commonly used for web development. It allows developers to add dynamic and interactive elements to websites. The document outlines what PHP is, how to install it, basic syntax rules, and common operations like variables, data types, functions for manipulating strings, and different types of operators.

1. php
• PHP is a server scripting language, and a
powerful tool for making dynamic and
interactive Web pages.
• Example:

2. What You Should Already Know
• Before you continue you should have a basic
understanding of the following:
• HTML
• CSS
• JavaScript

3. What is PHP?
• PHP is an acronym for "PHP: Hypertext
Preprocessor"
• PHP is a widely-used, open source scripting
language
• PHP scripts are executed on the server
• PHP is free to download and use

4. PHP 5 Installation

5. Set Up PHP on Your Own PC
• However, if your server does not support PHP,
you must:
• install a web server
• install PHP
• install a database, such as MySQL
• The official PHP website (PHP.net) has
installation instructions for
PHP: http://php.net/manual/en/install.php

6. What is a PHP File?
• PHP files can contain text, HTML, CSS,
JavaScript, and PHP code
• PHP code are executed on the server, and the
result is returned to the browser as plain
HTML
• PHP files have extension ".php"

7. Basic PHP Syntax
• PHP
• PHP Case Sensitivity
• Php comments

8. Output Variables
• The PHP echo statement is often used to
output data to the screen.

9. PHP Variables
• A variable can have a short name (like x and y) or a more
descriptive name (age, carname, total_volume).
Rules for PHP variables:
• 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 cannot start with a number
• A variable name can only contain alpha-numeric characters
and underscores (A-z, 0-9, and _ )
• Variable names are case-sensitive ($age and $AGE are two
different variables)

10. PHP is a Loosely Typed Language
* PHP automatically converts the variable to the
correct data type, depending on its value.
• In other languages such as C, C++, and Java,
the programmer must declare the name and
type of the variable before using it.

11. PHP Variables Scope
• In PHP, variables can be declared anywhere in
the script.
• The scope of a variable is the part of the script
where the variable can be referenced/used.
• PHP has three different variable scopes:
• local
• global
• static

12. PHP The static Keyword
• Normally, when a function is
completed/executed, all of its variables are
deleted. However, sometimes we want a local
variable NOT to be deleted. We need it for a
further job.

13. PHP 5 echo and print Statements
• 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.

14. PHP String Functions
• Get The Length of a String
• The PHP strlen() function returns the length of
a string.

15. PHP String Functions
• Count The Number of Words in a String
• The PHP str_word_count() function counts the
number of words in a string:

16. Reverse a String
• The PHP strrev() function reverses a string:

17. String Functions
• Search For a Specific Text Within a String
• The PHP strpos() function searches for a
specific text within a string.

18. String Functions
• Replace Text Within a String
• The PHP str_replace() function replaces some
characters with some other characters in a
string.
• echo str_replace("world", "Dolly", "Hello
world!"); // outputs Hello Dolly!

19. 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
• Array operators

20. PHP Arithmetic Operators

21. PHP Assignment Operators

22. PHP Comparison Operators

23. PHP Logical Operators

24. PHP String Operators

25. Thanks