PHP for WordPress

PHP for WordPress JOE CASABONA

What is PHP? ◦ Interpreted Programming Language ◦ Compare to
HTML, CSS, Javascript ◦ Processed by Server ◦ Often used to talk to Databases ◦ Allows for more dynamic content

Anatomy of a PHP Program ◦ PHP files must end
in .php ◦ PHP code opens with <?php and closes with ?> <?php PHP code lines go here ?>

<html> <head> <title>Hello World Script</title> </head> <body> Hello World </body>
</html> Hello World, HTML

<html> <head> <title>Hello World Script</title> </head> <body> <?php echo “Hello
World”; ?> </body> </html> Hello World, PHP

Variables Variables are a way to store information in order
to reference it later. Variables can be used to store names, numbers, and other important data. All PHP programs, including WordPress, heavily use variables. $age = 30;

Variables Variables can be letters/symbols (characters), words/phrases (Strings), or numbers
(integer or decimals/floats) $age = 30; $average = 27.5; $name = “Joe”; $first_letter = ‘J’;

Arrays Arrays are different from other variables. Arrays act as
  key -> value pairs. Let’s look at a collection of colors on the next slide. We have an array of size 4 (there are 4 elements), and we can access any one of these by referencing its key, or index. Indexing starts at 0 for arrays, so an array of size 4 will have indexes 0-3.

<?php echo $array[0]; //This will print “red” echo $array[3]; //This
will print “yellow” ?> Arrays <?php $colors = array( ‘red’, ‘blue’, ‘green’, ‘yellow’ ); ?>

<?php echo $joe[‘name’]; //This will print “Joe Casabona” echo $joe[‘age’];
//This will print “30” ?> Arrays <?php $joe = array(‘name’ => ‘Joe Casabona’, ‘age’ => 30, ‘profession’ => ‘Web Developer’); ?>

CONTROL STRUCTURES Control Structures are used in PHP to employ
logic to our code. They are what do the decision making. The most common of these control structures is if statements.

If Statements <?php if ( condition to check ){ ⁄⁄
code to execute if the condition is true } if ( condition to check ): ⁄⁄ code to execute if the condition is true endif; ?>

If Statements <?php if ( 10 >= 5 ) {
echo “10 is greater than or equal to 5”; } else { echo “10 is not greater than or equal to 5.”; } ?>

Logic Operators == != > < >= <= && ||
===

Loops Loops are used to repeat code or continually check
the condition of a statement. They are a fundamental part of WordPress; the important portion of WordPress code is called “the Loop.” We will look at two types of loops: While Loops and Foreach Loops.

While Loop <?php $i = 0; while( $i <= 10
) { echo “$i”; $i = $i + 1; } ?>

For Each Loop <?php foreach( $colors as $color) { echo
“$color”; } ?>

Functions Functions are reusable snippets of code that can be
called multiple times. You can imagine functions as variables for blocks of code. Functions can do one of two things: Return a variable or print something out.

Functions <?php function hello_world() { echo “Hello World”; } ?>
<?php function is_bigger() { return 10 >= 5; } ?>

Functions <?php function is_bigger($a, $b) { return $a >= $b;
} $bigger = is_bigger(10, 5); ?>

Any Questions? Joe Casabona Front End Developer wpinonemonth.com

PHP for WordPress

PHP for WordPress

Joe Casabona

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Transcript

PHP for WordPress JOE CASABONA

What is PHP? ◦ Interpreted Programming Language ◦ Compare to

Anatomy of a PHP Program ◦ PHP files must end

<html> <head> <title>Hello World Script</title> </head> <body> <p>Hello World</p> </body>

<html> <head> <title>Hello World Script</title> </head> <body> <p><?php echo “Hello

Variables Variables are a way to store information in order

Variables Variables can be letters/symbols (characters), words/phrases (Strings), or numbers

Arrays Arrays are different from other variables. Arrays act as

<?php echo $array[0]; //This will print “red” echo $array[3]; //This

<?php echo $joe[‘name’]; //This will print “Joe Casabona” echo $joe[‘age’];

CONTROL STRUCTURES Control Structures are used in PHP to employ

If Statements <?php if ( condition to check ){ ⁄⁄

If Statements <?php if ( 10 >= 5 ) {

Logic Operators == != > < >= <= && ||

Loops Loops are used to repeat code or continually check

While Loop <?php $i = 0; while( $i <= 10

For Each Loop <?php foreach( $colors as $color) { echo

Functions Functions are reusable snippets of code that can be

Functions <?php function hello_world() { echo “Hello World”; } ?>

Functions <?php function is_bigger($a, $b) { return $a >= $b;

Any Questions? Joe Casabona Front End Developer wpinonemonth.com