Page 243 - Beginning PHP 5.3

Chapter 8: Objects
You can then make a class implement an interface using the implements keyword:

class MyClass implements MyInterface {
public function myMethod1( $param1, $param2 ) {
// (implement the method here)
}

public function myMethod2( $param1, $param2 ) {
// (implement the method here)
}

}
To implement more than one interface at once, separate the interface names with commas:
class MyClass implements MyInterface1, MyInterface2 {

Try It Out Create and Use an Interface
The following example shows how to create and use a Sellable interface to turn two quite unrelated

classes — Television and TennisBall — into sellable items in an online store. Save the script as

interfaces.php in your document root folder and open it in your browser; you should see the result
shown in Figure 8 - 7 .

< !DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd” >
< html xmlns=”http://www.w3.org/1999/xhtml” xml:lang=”en” lang=”en” >
< head >
< title > Creating and Using an Interface < /title >
< link rel=”stylesheet” type=”text/css” href=”common.css” / >
< /head >
< body >
< h1 > Creating and Using an Interface < /h1 >

< ?php

interface Sellable {
public function addStock( $numItems );
public function sellItem();
public function getStockLevel();
}

class Television implements Sellable {
private $_screenSize;
private $_stockLevel;

public function getScreenSize() {
return $this- > _screenSize;
}

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