PHP WEBDEVELOPMENT COURSE PART- 1.pptx

PHP BASICS

1. PHP

2. Introduction to PHP (Hypertext Preprocessor PHP stands for PHP: Hypertext Preprocessor PHP is a server-side scripting language, like ASP PHP scripts are executed on the server PHP supports many databases (MySQL, Informix, Oracle, Sybase, Solid, PostgreSQL , Generic ODBC, etc..) PHP is an open source software (OSS) PHP is free to download and use

3. What is a PHP File ? PHP files may contain text, HTML tags and scripts PHP files are returned to the browser as plain HTML PHP files have a file extension of ". php ", ".php3", or ". phtml " What Can PHP Do? PHP can generate dynamic page content 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

4. PHP Syntax A PHP script can be placed anywhere in the document. A PHP script starts with : <? php And ends with: ?> PHP statements end with a semicolon (;)

5. PHP Case Sensitivity In PHP, all keywords (e.g. if, else, while, echo, etc.), classes, functions, and user-defined functions are NOT case-sensitive. In the example below, all three echo statements below are legal (and equal ) However; all variable names are case-sensitive.

6. Comments A comment in PHP code is a line that is not read/executed as part of the program. Its only purpose is to be read by someone who is looking at the code. In PHP, we use // to make a single-line comment or /* and */ to make a large comment block .

7. Variables Variables are used for storing values, such as numbers, strings or functions results, so that they can be used many times in a script . All variables in PHP start with a ( $ )sign symbol. The correct way of setting a variable in PHP

8. 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 $AGE are two different variables) A variable name should not contain spaces. If a variable name is more than one word, it should be separated with underscore ($ my_string ), or with capitalization ($ myString )

9. Variable 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

10. Global variable A variable declared  outside  a function has a GLOBAL SCOPE and can only be accessed outside a function: