archived-presentations/slides/advphp/classes.xml

<slide title="Classes">
<blurb>
Classes are data containers which store functions (called 
methods) and variables (called properties).
</blurb>
<blurb>Classes are defined with the class declaration:</blurb>
<example 
	fontsize="1.2em" 
	title="Class Declaration" 
	type="php">
<![CDATA[<?php 
class Simple {
}
?>]]>
</example>
<blurb> Properties are defined with the var declaration:</blurb>
<example 
	fontsize="1.2em" 
	title="Property Declaration" 
	type="php">
<![CDATA[<?php
class Simple {
	var $someprop;
}
?>]]>
</example>
<blurb> Methods are defined with the function declaration:</blurb>
<example 
	fontsize="1.2em" 
	title="Method Declaration" 
	type="php">
<![CDATA[<?php
class Simple {
	var $someprop;

	function somemethod ()
	{
	    print ('HALLO!');
	}
}
?>]]>
</example>
<blurb> In order access class properties and methods, you can 
use the default $this object, which is created alongside every
object instance.</blurb>
<example 
	fontsize="1.2em" 
	title="$this" 
	type="php">
<![CDATA[<?php
class Simple {
	var $someprop;

	function somemethod ()
	{
	    $this->someprop = 'Irgendwie neeee?';

	    print ('Ja, das ist doch ' . $this->someprop);
	}

	function anothermethod ()
	{
	    $this->somemethod ();
	}
}
?>]]>
</example>
<blurb> Constructors are methods that have the same name 
as the class:</blurb>
<example 
	fontsize="1.2em" 
	type="php" 
	title="Constructors">
<![CDATA[<?php
class Simple {
	var $someprop;

	function Simple () 
	{
	    $this->someprop = get_defined_functions ();
	}

	function somemethod ()
	{
	    $this->someprop = 'Irgendwie neeee?';

	    print ('Ja, das ist doch ' . $this->someprop);
	}

	function anothermethod ()
	{
	    $this->somemethod ();
	}
}
?>]]>
</example>
</slide>