Basics of PHPSACHEEN DHANJIE

Sacheen DhanjieSenior Developer @ Afrihost.com

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

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);

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/

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

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

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

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

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))

What if $bob?

Bob Ross or just Ross?

What if $bob• (!$bob)

• If $bob was null; //true• If $bob was 1; //false• If $bob was false; //true• If $bob was 0; //true

Conditions

Conditions

Arrays

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

I hate else

Limit Nesting

Any suggestions to neaten this up?

Limit Nesting

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

Do one thing and do it well

Simple Objects – Object Oriented Programing

• Classes• Can be instantiated• Has instance variables• getters• Setters [mutators]• Can be extended• Accessibility

• - public / private / protected

User Class

Using the User Class

Extend the User Class

Using the Reseller Class

Cool Functions

Something Cool