getting started with php
DESCRIPTION
Getting started with PHP talk given at the MemphisPHP.org User group meet up in September 2013.TRANSCRIPT
Getting Started with PHPMemphisPHP.org
Joe Ferguson - [email protected]
Professionally● Web Developer at RocketFuel● PHP / LAMP Focused
Semi Professional● Co-Organizer for MemphisPHP.org● MidsouthMakers - Hackerspace Leader● HACKmemphis.com Organizer
Who is this guy?
It’s a recursive anagram…
PHP: Hypertext Preprocessor is a widely used, general-purpose scripting language that was originally designed for web development to produce dynamic web pages
What is PHP?
● Widespread Availability○ PHP is now installed on more than 244 million
websites and 2.1 million web servers (Source: Wikipedia)
● Ease of use.○ Extremely simple for newcomers○ Advanced features for professional programmers○ Looslely typed
● Great Community Support● Many corporations throwing support
behind PHP projects
Why use PHP?
Who uses it? What runs on PHP?
...and many, MANY others
<html> <head> <title>Example 1 - Getting Started with PHP<</title> </head> <body> <?php echo '<p>Hello World</p>'; ?> </body></html>
Jumping into PHP - Example 1
You can add any content to a PHP file.
Anything not between PHP tags is ignored by PHP.
Using echo, you can print from PHP. As example 1 shows, even PHP.
Example 1 - Basic HTML + PHP
PHP is very easy to pick up and run with.
This is one of the main reasons it is so widespread.
Looks easy right?
$_GET Variables come from the URLBad:<?php$name = $_GET['name'];?>NEVER trust data from your users!
Good:<?phpif(isset($_GET['name'])){ $name = filter_var($_GET['name'],FILTER_SANITIZE_STRING);}?>
Getting Data from the User
So what is happening?● First we check if the name exists by
looking at $_GET[‘name’]○ if(isset($_GET['name'])){
● If it does exist, we pass it to a function to sanitize the input and set the results equal to $name○ $name = filter_var($_GET['name'],FILTER_SANITIZE_STRING);
Getting Data from the User
● isset● empty● filter_var● arrays● strings● omgwtf!
The best PHP resources:● phptherightway.com● php.net
I can’t keep track of all this!
PHP Specification Request (PSR)
The Framework Interop Group:● PSR-0● PSR-1● PSR-2
Other Styles:● PEAR Coding Standards● Zend Coding Standards
OMG your { are on the wrong line!
There are subtle differences among the PSR coding styles approved by the FIG.
If you’re wanting to maximize your reusability: pick a PSR similar to the code you are working with.
Most projects won’t take code if it doesn’t match the style they have adopted.
Why so many? What do I use?
Strings● echo ‘PHP is my favorite language’;● $variable = ‘PHP is amazing’;● echo "PHP! you'll be astonished";● echo 'PHP! you\'ll be astonished';Concatenation● echo "Hello, " . $prefix . " " . $name;Single quote strings do not get parsed.Double quote strings get parsed. Are slower than single quote strings because of this.
Before we get too complicated:
Simple Arrays:<?php$fruit = array();$fruit[] = 'apple';$fruit[] = 'pear';$fruit[] = 'orange';$fruit[] = 'lemon';$fruit[] = 'pineapple';?>
Arrays - associating values to keys
$food = array();$food['fruit'] = array();$food['fruit'][] = 'apple';$food['fruit'][] = 'pear';$food['fruit'][] = 'orange';$food['fruit'][] = 'lemon';$food['fruit'][] = 'pineapple';$food['meat'] = array();$food['meat'][] = 'bacon';$food['meat'][] = 'steak';$food['meat'][] = 'chicken';$food['meat'][] = 'fish';
Multidimensional Arrays - Ex 5
● We know that PHP is awesome● We know A LOT of people use PHP● We’ve greeted the world of PHP● We have seen how to get data from users● We are absolute EXPERTS at Arrays
The Story So Far
Conditions
$name = 'Joe';//$name = 'Bill the pony';if($name == 'Joe'){ echo '<p>Hello Joe, welcome back</p>';} else { echo '<p>Hello ' . $name . '</p>';}
Putting it together… Example 6
Foreach steps through each item.
You perform some action on each item.
foreach($fruit AS $key => $value){ echo '<li>' . $value . '</p>'; }
For Loops - Example 7
While loops perform the action while a condition is met and then stops.
$fruit_count = count($fruit); $f = 0; while ($f < $fruit_count){ echo '<li>' . $fruit[$f] . '</li>'; $f++; }
While Loops - Example 8
function getFruit(){ $fruit = array(); $fruit[] = 'apple'; $fruit[] = 'pear'; $fruit[] = 'orange'; $fruit[] = 'lemon'; $fruit[] = 'pineapple'; return $fruit;}
FUNctions - Example 9
Using the previous getFruit function:
$fruit = getFruit();
$fruit is now an array created by the function
Using Functions - Example 9
● You can pass data into an array by adding arguments
function getFruitOrMeat($fruit_or_meat){…}$fruit_or_meat is data we are passing into the getFruitOrMeat function
Function Arguments Example 10
The best PHP resources:● phptherightway.com● php.net
Online Learning:● codecademy.com● php.net/manual/en/getting-started.php
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