This document provides an overview of basic PHP concepts, including what PHP is, how to work with variables, naming conventions, numbers and casting, operators, conditions, arrays, limiting nested code, object-oriented programming with classes, and some examples of working with a User class and extending it to a Reseller class. It covers fundamental PHP syntax and structures to get started with the language.

1. Basics of PHP
SACHEEN DHANJIE

2. Sacheen Dhanjie
Senior Developer @ Afrihost.com

3. What is PHP?
• Hypertext PreProcessor
• Built on C
• Made for the web, but can run on the
command line
• We run all our processing scripts via the
CLI

4. Variables
• The $ is used to prefix a string, which denotes a variable
• $name = “BOB”; //this assigns the variable
• $sentence = “my name is $name”; // what will this out put?
• $concatenate = “my name is ”.$name; //what will this
output?
• Display information
• echo $sentence;
• print($sentence);

5. Naming Variables
• $name; // lower case for single words
• $lastName; //camel case for more than one word
• $animalsArray = (‘cow’,’dog’); // not good
• $animals = (‘cow’,’dog’);
• $userObj = new User() // not good
• $user = new User();
• http://www.php-fig.org/psr/

6. Numbers
• echo 2 + 2; ?
• echo '2' + 2; ?
• ;echo '2' + "2"; ?
• echo 2 + 'c’; ?

7. Numbers
• Everything in PHP is cast to an integer by default
• echo 2 + 2; //4
• echo '2' + 2; //4
• ;echo '2' + "2"; //4
• echo 2 + 'c’; //2

8. Casting
• What is casting?
• Casting means making a value a particular type
• $i = 2.332242;
• (int) $i; //2
• (float) $i; // 2.332242
• (string) $i; // 2.332242

9. Casting
• Why do we care about casting?
• When we interact with data, the language you work with may assume
things
• If you parse and XML message - https://en.wikipedia.org/wiki/XML
• <amount>10.32</amount>
• Using an XML parser, the 10.32 will be assumed as an integer, 10 and
not 10.32
• Casting the value will give you the 10.32
• These things are picked up as you learn to code

10. Operations
• < //less than
• > //greater than
• <= //less than or equal to
• >= //greater than or equal to
• = //assignment $i =1;
• == //equality (1 == true)
• === //type equlity (1 === true)
• ! //negation - you should be carful (!$bob instanceof
Class) rather (!($bob instanceof Class))

11. What if $bob?
Bob Ross or just Ross?

12. What if $bob
• (!$bob)
• If $bob was null; //true
• If $bob was 1; //false
• If $bob was false; //true
• If $bob was 0; //true

13. Conditions

14. Conditions

15. Arrays

16. Arrays
• Can be used to represent a data source [database, file,
etc.]
• There are many built in functions for arrays.
http://php.net/manual/en/function.array.php
• array_sum($amounts); //R24.23;
• Database queries can be returned as arrays

17. I hate else

18. Limit Nesting
Any suggestions to neaten this up?

19. Limit Nesting

20. Nesting
• Keep your nesting to a minimal
• The deeper you nest the more complex you code
becomes
• The more it is to debug
• Refactor if your code becomes a mess.
• Make smaller functions for each complex bit.
• Avoid else
• Return early is not a bad thing

21. Do one thing and do it well

22. Simple Objects – Object Oriented Programing
• Classes
• Can be instantiated
• Has instance variables
• getters
• Setters [mutators]
• Can be extended
• Accessibility
• - public / private / protected

23. User Class

24. Using the User Class

25. Extend the User Class

26. Using the Reseller Class

27. Cool Functions

28. Something Cool