PHP Module 1: Introduction to PHP

Questions and Answers

Who developed PHP initially?

apache developers

Rasmus Lerdorf (correct)

Zeev Suraski and Andi Gutmans

mysql team

What does PHP stand for currently?

Powerful Hypertext Processor

PHP: Hyperactive Processing

PHP: Hypertext Preprocessor (correct)

Personal Home Page

What is a key feature of PHP as a server-side scripting language?

It only supports MySQL database

It is a loosely typed language (correct)

It is a client-side scripting language

It is a statically typed language

What is required to run PHP scripts?

Web server, database, and a code editor Signup and view all the answers

How do you enclose PHP code?

<?php> Signup and view all the answers

What is the purpose of the 'echo' and 'print' statements in PHP?

To output data to the screen Signup and view all the answers

What is type casting in PHP?

Changing variable types explicitly Signup and view all the answers

What is the purpose of the 'gettype()' function in PHP?

To get the data type of a variable Signup and view all the answers

What is the primary function of the foreach loop in PHP?

To iterate over an array and perform an action on each element Signup and view all the answers

What is the purpose of the define() function in PHP?

To define a constant Signup and view all the answers

What is the difference between the GET and POST methods in PHP?

GET appends data to the URL, while POST sends data in the request body Signup and view all the answers

What is the purpose of the preg_match() function in PHP?

To validate a regular expression pattern Signup and view all the answers

What is a primary key in a database?

A unique identifier for each record in a table Signup and view all the answers

What is the purpose of the session_start() function in PHP?

To start a new session Signup and view all the answers

What is the purpose of the explode() function in PHP?

To split a string into an array Signup and view all the answers

What is the purpose of the var_dump() function in PHP?

To output the value and data type of a variable Signup and view all the answers

Study Notes

Module 1: Introduction to PHP

PHP was developed by Rasmus Lerdorf in 1994/1995
Originally stood for Personal Home Page, later changed to Hypertext Preprocessor
Key features of PHP:
- Server-side scripting language
- Loosely typed language
- Many built-in libraries and functions
- Supports many databases
- Free and open source
Software requirements:
- Operating System: Windows, Linux, or Mac
- Web Server: Apache, Google Web Server, etc.
- Database: MySQL, Oracle, etc.
- Code Editor: Notepad++, Eclipse, Dreamweaver, etc.
To run PHP scripts:
- Install XAMPP/WAMP
- Start Apache and MySQL services
- Save PHP files in htdocs folder
- Access via localhost in browser
PHP syntax basics:
- PHP code is enclosed in <?php ?> tags
- Statements end with a semicolon
- echo and print are used for output
- Variables start with a $ symbol
- Comments: // for single line, /* */ for multi-line
PHP data types:
- Scalar: boolean, integer, float, string
- Compound: array, object
- Special: NULL, resource
Type casting:
- Changing variable types explicitly
- Examples: (int), (float), (string), (array), (object), etc.

Module 2: PHP Operators and Control Structures

Arithmetic operators: +, -, *, /, %, **
Assignment operators: =, +=, -=, *=, /=, %=, etc.
Comparison operators: ==, ===, !=, !==, <, >, etc.
Increment/Decrement operators: ++, --
Logical operators: &&, ||, !, and, or, xor
String operators: . (concatenation)
Array operators: +, ==, ===, !=, !==
Operator precedence and associativity:
- Understand order of operations
- Use parentheses to clarify intent
Control structures:
- Conditional: if, else, elseif, switch
- Loops: while, do-while, for, foreach
- Break, continue, goto statements
Alternative syntax:
- Replace { } with : and endif;, endwhile;, endfor;, etc.

Module 3: PHP Arrays and User-Defined Functions

Arrays:
- Indexed arrays: numeric keys
- Associative arrays: string keys
- Multidimensional arrays: arrays within arrays
Array functions:
- print_r() and var_dump() for debugging
- sort(), rsort(), asort(), arsort(), ksort(), krsort()
- unset(), explode(), implode()
Looping through arrays:
- foreach loop
User-defined functions:
- function keyword
- Parameters and return values
- Variable scope: global, local, static

Module 4: PHP Predefined Functions

Constants:
- define() function
Including files:
- include, require, include_once, require_once
Mathematical functions:
- rand(), ceil(), floor(), min(), max(), number_format()
String manipulation functions:
- strlen(), strpos(), strrev(), strtolower(), strtoupper(), substr()
- ucfirst(), ucwords(), trim(), ltrim(), rtrim(), strip_tags()
Date and time functions:
- date(), mktime(), strtotime()
- Date format characters (Y, m, d, H, i, s, etc.)

Module 5: PHP Web Forms and Form Validation

Superglobal variables:
- SERVER,_SERVER, SERVER,_GET, POST,_POST, POST,_REQUEST, COOKIE,_COOKIE, COOKIE,_SESSION, $_ENV
Form handling:
- Difference between GET and POST methods
- Processing form data
Cookies:
- setcookie() function
- Reading and deleting cookies
Sessions:
- session_start(), session_destroy()
- Setting and unsetting session variables
Regular expressions:
- preg_match() function
- Common regex patterns and modifiers
- Form validation using regex (e.g., email validation)

Module 6: MySQL Database

Introduction to databases:
- Definition: Ordered collection of information for quick access
- Structure: Tables, records, and fields
- Types: Flat-file vs. Relational databases
- Key concepts: Primary key, Foreign key, Normalization
MySQL basics:
- Open-source relational database management system
- Features: High availability, scalability, and performance