策略模式（感谢mpeg提供代码）

<?php
interface IStrategy {
function filter( $record );
}
class FindAfterStrategy implements IStrategy {
private $_name;

public function __construct( $name ) {
$this->_name = $name;
}

public function filter( $record ) {
return strcmp( $this->_name, $record ) <= 0;
}
}
class RandomStrategy implements IStrategy {

public function filter( $record ) {
return rand( 0, 1 ) >= 0.5;
}
}
class UserList {
private $_list = array();

public function __construct( $names ) {

if ( $names != null ) {
foreach( $names as $name ) {
$this->_list []= $name;
}
}
}
public function add( $name ) {
$this->_list []= $name;
}
public function find( $filter ) {
$recs = array();
foreach( $this->_list as $user ) {
if ( $filter->filter( $user ) )
$recs []= $user;
}
return $recs;
}
}
$ul = new UserList( array( "Andzy", "Jack", "Lori", "Megan" ) );
$f1 = $ul->find( new FindAfterStrategy( "J" ) );
print_r( $f1 );
$f2 = $ul->find( new RandomStrategy() );
print_r( $f2 );
?>

mpeg的网站是：www.phpubb.com