<?php 
class MyClass{ 
    private $_counter = 0; 
    public function increment() { 
        return $this->_counter++;
    }
}
?>

 <?php 
session_start(); 
if (! isset($_SESSION['myObject'])) { 
    require_once __DIR__ . '/MyClass.php'; 
    $_SESSION['myObject'] = new MyClass(); 
}
 
echo get_class($_SESSION['myObject']), "\n";
echo $_SESSION['myObject']->increment(), "\n"; 
?>

 <?php 
require_once __DIR__ . '/MyClass.php'; 
session_start();
if (! isset($_SESSION['myObject'])) { 
    $_SESSION['myObject'] = new MyClass(); 
} 
echo get_class($_SESSION['myObject']), "\n"; 
echo $_SESSION['myObject']->increment(), "\n"; 
?>

<?php 
session_start(); 
if (! isset($_SESSION['myObject'])) { 
    require_once __DIR__ . '/MyClass.php'; 
    $_SESSION['myObject'] = serialize(new MyClass()); 
} 
$myObject = unserialize($_SESSION['myObject']); 
echo get_class($myObject), "\n"; 
echo $myObject--->increment(), "\n"; 
?>

$ php -r 'class A{var $x=0; function p(){echo ++$x;}} $a=new A(); echo serialize($a);'
O:1:"A":1:{s:1:"x";i:0;}

$ php -r '$a=unserialize("O:1:\"A\":1:{s:1:\"x\";i:0;}");$a->p();'

<?php
session_start();
$key = 'a';
if( !isset($_SESSION[$key]) ){
    require_once strtoupper($key) . '.php';
    $class = strtoupper($key);
    $_SESSION[$key] = serialize(new $class());
}
// try to include class declaration file before use it
if( !class_exists(strtoupper($key), FALSE) ){
    require_once strtoupper($key). '.php';
    $obj = unserialize($_SESSION[$key]);
    // TODO: whatever you what to do with $obj ...
}
?>

pwwang@pwwang-xxx:~$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.5.8 Source distribution
 
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> use database;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
mysql> select id from table order by rand(1);
+----+
| id |
+----+
|  1 |
|  3 |
|  8 |
|  4 |
|  7 |
|  6 |
|  9 |
|  5 |
+----+
8 rows in set (0.00 sec)
 
mysql> Bye
pwwang@pwwang-xxx:~$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.5.8 Source distribution
 
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> use database;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
mysql> select id from table order by rand(1);
+----+
| id |
+----+
|  1 |
|  3 |
|  8 |
|  4 |
|  7 |
|  6 |
|  9 |
|  5 |
+----+
8 rows in set (0.00 sec)
 
mysql> Bye

pwwang@pwwang-xxx:~$ sudo lampp restart
[sudo] password for pwwang:
Stopping XAMPP for Linux 1.7.4...
XAMPP: Stopping Apache with SSL...
XAMPP: Stopping MySQL...
XAMPP: Stopping ProFTPD...
XAMPP stopped.
Starting XAMPP for Linux 1.7.4...
XAMPP: Starting Apache with SSL (and PHP5)...
XAMPP: Starting MySQL...
XAMPP: Starting ProFTPD...
XAMPP for Linux started.
pwwang@pwwang-xxx:~$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.8 Source distribution
 
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> use database;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
mysql> select id from table order by rand(1);
+----+
| id |
+----+
|  1 |
|  3 |
|  8 |
|  4 |
|  7 |
|  6 |
|  9 |
|  5 |
+----+
8 rows in set (0.00 sec)

mysql> select RAND(1);
+---------------------+
| RAND(1)             |
+---------------------+
| 0.40540353712197724 |
+---------------------+
1 row in set (0.02 sec)
 
mysql> select RAND(1);
+---------------------+
| RAND(1)             |
+---------------------+
| 0.40540353712197724 |
+---------------------+
1 row in set (0.00 sec)

$seed = $_GET['seed']; // 你也可以用session, cookie等方式来存储这个值
if( !isset($_GET['seed']) ){  
    $seed = rand();
}
$sql = "SELECT id FROM table ORDER BY RAND($seed) LIMIT $offset, $limit;";

$serial = explode(',', $_GET['serial']);
if( !$serial ){
    $maxid = $db->get_value("SELECT MAX(id) FROM table");
    $serial = range(1, $maxid);
    shuffle($serial);
}
$ids_array = array_slice($serial, $offset, $limit);
$ids = implode(',', $ids_array);
$sql = "SELECT id FROM table WHERE id IN ($ids);";

$serial = $db->get_value("SELECT group_concat(id) FROM table");
$serial = explode(',', $serial);

<root>
    <a>
        <b>test</b>
    </a>
</root>

<root>
<a></b>
<b></a>
</root>

<tag />

            function show_del($id){
                return "<input type=button value=$id>";    
            }
            $pagination = new paginate(array(
                sql     => 'SELECT * FROM `dishes`',
                theader    => 'ID,Dish_name,Dish_price,Dish_Dir,Manipulation',
                tbody    => '<tr><td>{var:dish_id}</td><td>{var:dish_name}</td><td>{var:dish_sm_price}</td><td>{var:dish_dir}</td><td>{var:dish_id;fun:show_del}</td></tr>',
                linkmode => 1,
                orderbys => 'dish_id:ID;dish_name:NAME;dish_sm_price:PRICE',
                clientsort => 1
            ));    
            $pagination->show();

            function show_del($id){
                return "<input type=button value=$id>";    
            }
            $pagination = new paginate(array(
                sql     => 'SELECT * FROM `dishes`',
                theader    => 'ID,Dish_name,Dish_price,Dish_Dir,Manipulation',
                tbody => '<div>dish_id:{var:dish_id}<br>dish_name:{var:dish_name}<br>dish_price:{var:dish_sm_price}</div>',
                mode =>1,
                orderbys => 'dish_id:ID;dish_name:NAME;dish_sm_price:PRICE',
                clientsort => 1
            ));    
            $pagination->show();

class paginate{
    var $data = array();    // data show in this page
    var $count;                // total count of the records
    var $page;                // page number of this page
    var $sql;                // total records sql, including 'order by' clause
    var $limit = 12;        // how many records to show in this page
    var $mode = 0;            // 2 modes, 0 for one record in one line with headers; 
                            //          1 for multiple records in one line without headers
    var $theaders;            // headers for mode 0, like "ID,姓名,电话,..."
    var $tbody;                // cycle body
                            // for mode 0, $tbody is like "<tr><td>{var:id;fun:fun1}</td>...<td>{var:value;fun:fun2}</td></tr>"
                            // for mode 1, $tbody is like "<div>{var:id;fun:fun1}</div>"
    var $rnpl = 4;            // Records Number Per Line, just for mode 1.
    var $linkmode = 0;        // temporarily 2 like modes. One displays page numbers by combo box; another displays them directly.
    var $rnthis;            // Records Number in THIS page. It equals to $limit, but probably not in the last page.
    var $colnames = array();// colomn names in this table
    var $pagenum;            // total page number
    var $maxpagenum = 11;    // for linkmode 1, how many page numbers to show, odd number required    
    var $tableid = 'paginate_table';
    var $orderbys;            // "id:序号;name:姓名;phone:电话"
    var $orderby;
    var $rank = 'ASC';
    var $clientsort = 0;    // close client sort as default
    function paginate($opts){
        global $db;            // ensure include db.class.php
        $this->sql        = $opts['sql'];
        $theader        = $opts['theader'];
        $this->theaders = split(',',$theader);
        $this->tbody    = $opts['tbody'];
        $this->page     = $_GET['page'];
        if($opts['limit'])        $this->limit    = $opts['limit'];
        if($opts['mode'])        $this->mode        = $opts['mode'];
        if($opts['rnpl'])        $this->rnpl        = $opts['rnpl'];
        if($opts['linkmode'])    $this->linkmode    = $opts['linkmode'];
        if(!$this->page)         $this->page     = 1;
        $this->count     = $db->num_rows($this->sql);
        $this->pagenum = ceil($this->count/$this->limit);
        if($this->page < 1) $this->page = 1;
        if($this->page > $this->pagenum) $this->page = $this->pagenum;
        if($opts['orderbys'])$this->orderbys = $opts['orderbys'];
        if($this->orderbys){
            $this->sql = preg_replace('/order\s+by\s+.+(?:\s+(?:a)|(?:de)sc)?/i','',$this->sql);
            $getorderby = split(' ',$_GET['orderby']);
            if($getorderby[0]) $this->orderby = $getorderby[0];
            else { 
                $obs = split(':',$this->orderbys);
                $this->orderby = $obs[0];
            }
            if($getorderby[1]) $this->rank = $getorderby[1];
            $this->sql .= " ORDER BY `".$this->orderby."` ".$this->rank;
        }
        $thissql        = $this->sql." limit ".($this->page-1)*$this->limit.",".$this->limit;
        $this->data     = $db->fetch_all($thissql);
        $this->rnthis    = $db->num_rows($thissql);
        preg_match_all("/\{var:(.+?)(;fun:.+?)?\}/",$this->tbody,$matches);
        $this->colnames    = $matches[1];
        if($opts['maxpagenum'])$this->maxpagenum = $opts['maxpagenum'];
        if($opts['tableid'])$this->tableid = $opts['tableid'];
        if($opts['clientsort'])$this->clientsort = $opts['clientsort'];
    }
 
    function getHeaders(){
        if(!$this->mode){
            $headers_str = "<thead><tr>";
            foreach ($this->theaders as $h){
                $headers_str .= "<th>$h</th>";    
            }
            $headers_str .= "</tr></thead>\n";
            return $headers_str;
        }
        return '';
    }
 
    function show(){
        $show_str = "";
        if($this->orderbys){
            $show_str .= "排序依据:   ";
            $orderbyss = split(';',$this->orderbys);
            foreach ($orderbyss as $ob){
                preg_match("/^(.+?)\:(.+)$/",$ob,$matches);    
                if($this->orderby == $matches[1]){
                    $show_str .= $this->getLink("orderby",$this->orderby." ".($this->rank=='ASC'?'DESC':'ASC'),$matches[2].($this->rank=='ASC'?'↑':'↓'),"title=按".$matches[2].($this->rank=='ASC'?'降':'升')."序排列")."   ";
                } else {
                    $show_str .= $this->getLink("orderby",$matches[1]." ASC",$matches[2].'☆',"title=按".$matches[2]."升序排列")."   ";
                }
            }
        }
        $show_str .= '<table id="'.$this->tableid.'" cellspacing=1 '.($this->clientsort?'clientsort=1':'').'>';
        if($this->mode){
            $show_str .= '<tbody>';
            for($i=0; $i<ceil($this->rnthis/$this->rnpl); $i++){
                $show_str .= "<tr>";
                for($j=0; $j<$this->rnpl; $j++){  // ---------
                    $show_str .= "<td>";
                    $body = $this->tbody;
                    for($k=0; $k<count($this->colnames); $k++){
                        $body = preg_replace("/\{var:(".preg_quote($this->colnames[$k]).")(;fun:.+?)?\}/","{var:".$this->data[$i*$this->rnpl+$j][$this->colnames[$k]]."$2}",$body);
                    }
                    if($j < $this->rnthis-$i*$this->rnpl) $show_str .= preg_replace("/\{var:([\s\S]+?)(?:;fun:(.+?))?\}/e","$2('$1')",$body);
                    $show_str .= "</td>";    
                }
                $show_str .= "</tr>";
            }
        } else {
            $show_str .= $this->getHeaders();
            $show_str .= '<tbody>';
            for($j=0; $j<$this->rnthis; $j++){  // ---------
                $body = $this->tbody;
                for($k=0; $k<count($this->colnames); $k++){
                    $body = preg_replace("/\{var:(".preg_quote($this->colnames[$k]).")(;fun:.+?)?\}/","{var:".$this->data[$j][$this->colnames[$k]]."$2}",$body);
                }
                $show_str .= preg_replace("/\{var:([\s\S]+?)(?:;fun:(.+?))?\}/e","$2('$1')",$body);
            }
        }
        $show_str .= '</tbody>';
        $show_str .= $this->getLinks();
        $show_str .= '</table>';
        echo $show_str;
    }
 
    function getHref($parms, $values){
        $ps = $_GET;
        if(is_array($parms)){
            for($i=0; $i<count($parms); $i++){
                $ps[$parms[$i]] = $values[$i];
            }
        } else {
            $ps[$parms] = $values;
        }
        $link = $_SERVER['PHP_SELF']."?";
        foreach ($ps as $k => $v){
            $link .= $k."=".urlencode($v)."&";
        }
        if(substr($link,-1) == "&") $link = substr($link,0,-1);
        return $link;        
    }
 
    function getLink($parms, $values, $str="", $attr = ""){
        return "<a href='".$this->getHref($parms, $values)."' $attr>$str</a>";
    }
 
    function getLinks(){
        $links_str = "<tfoot><tr><td colspan=".($this->mode?$this->rnpl:count($this->theaders))." style='text-align:center'>";
        if(!$this->linkmode) $links_str .= "第".(($this->page-1)*$this->limit+1)."~".(($this->page-1)*$this->limit+$this->rnthis)."条/共".$this->count."条记录 ";
        $links_str .= "[".($this->page>1?$this->getLink("page",1,"首页"):"首页")."] ";
        $links_str .= "[".($this->page>1?$this->getLink("page",$this->page-1,"上页"):"上页")."] ";
        if($this->linkmode){
            if($this->pagenum <= $this->maxpagenum){
                for($i=1; $i<=$this->pagenum; $i++){
                    if($this->page == $i) $links_str .= $this->getLink("page",$i,$i,"class=thispage")." ";
                    else $links_str .= $this->getLink("page",$i,$i)." ";
                }
            } else {
                if($this->page <= ($this->maxpagenum+1)/2) $startnum = 1;
                else $startnum = $this->page - ($this->maxpagenum+1)/2 + 1;
                if($this->pagenum - $this->page < ($this->maxpagenum+1)/2) $endnum = $this->pagenum;
                else $endnum = $this->page + ($this->maxpagenum+1)/2 - 1;
                if($startnum > 1){
                    $links_str .= $this->getLink("page",$startnum-1,"...");
                }
                for($i=$startnum; $i<=$endnum; $i++){
                    if($this->page == $i) $links_str .= $this->getLink("page",$i,$i,"clas=thispage")." ";
                    else $links_str .= $this->getLink("page",$i,$i)." ";
                }
                if($endnum < $this->pagenum){
                    $links_str .= $this->getLink("page",$endnum+1,"...");
                }
            }
        }
        $links_str .= "[".($this->page<$this->pagenum?$this->getLink("page",$this->page+1,"下页"):"下页")."] ";
        $links_str .= "[".($this->page<$this->pagenum?$this->getLink("page",$this->pagenum,"尾页"):"尾页")."] ";
        if(!$this->linkmode){
            $links_str .= "第<select onchange=\"javascript:location='".$this->getHref("page","")."'.replace('page=','page='+this.value)\">\n";
            for($i=1; $i<=$this->pagenum; $i++){
                if($i == $this->page) $links_str .= "<option value=".$i." selected>".$i."</option>\n";
                else $links_str .= "<option value=".$i." >".$i."</option>\n";    
            }
            $links_str .= "</select>页/";
        }
        $links_str .= "共".$this->pagenum."页</td></tr></tfoot>";
        return $links_str;
    }
}

function setpaginatestyle(paginate_table_id){
    if(paginate_table_id == undefined) paginate_table_id = '#paginate_table';
    pbody = paginate_table_id + '>tbody>';
    phead = paginate_table_id + '>thead>';
    pfoot = paginate_table_id + '>tfoot>';
    var tablebordercolor = '#5d7e49';
    var tdheight = '24px';
    var tdpadding = '2px';
    var oddtrbgcolor = '#b4bcaf';
    var eventrbgcolor = '#fff';
    var overtrbgcolor = '#dedfdd';
    var thbgcolor = '#8b9f7f';
    var thcolor = '#fff';
    var footerbgcolor = '#fff';
    var footeraborder = '1px 3px 1px 3px';
    var tablewidth = '450px';
    $(paginate_table_id).css({
        'background-color':tablebordercolor,
        'width':tablewidth
    });
    $(pbody+'tr>td').add(phead+'tr>th').add(pfoot+'tr>td').css({
        'padding':tdpadding,
        'height':tdheight
    });
    $(phead+'tr').css({
        'background-color':thbgcolor,
        'color':thcolor
    });
 
    $(pbody+'tr:odd')
                    .css('background-color',oddtrbgcolor)
                    .hover(
        function(){
            $(this).css({'background-color':overtrbgcolor});    
        },
        function(){
            $(this).css({'background-color':oddtrbgcolor});
        }        
    );
    $(pbody+'tr:even')
                     .css('background-color',eventrbgcolor)
                     .hover(
        function(){
            $(this).css('background-color',overtrbgcolor);    
        },
        function(){
            $(this).css('background-color',eventrbgcolor);
        }        
    );        
    $(pfoot+'tr').css('background-color',footerbgcolor).unbind();
    $(pfoot+'tr a').css('padding',footeraborder);
    $(pfoot+'tr a.thispage').css({
        'background-color':oddtrbgcolor,
        'border':'1px solid '+tablebordercolor
    });
    if($(paginate_table_id).attr('clientsort')){
        $('head').append('<script language="javascript" src="js/jquery.tablesorter.js"></script>');
        $(paginate_table_id).tablesorter();
    }
}
 
$(document).ready(function(){
    setpaginatestyle();    
});

 
<?php
class varhead{
var title;
function varhead(title='welcome'){
$this->title=title;
}
function setTitle(title='welcome'){
$this->title=title;
}
}
$varhead=new varhead();
//我先定义了这样一个类,　是用来设置网页的各种头部信息的.
//并且将它实例化
function isHome(){
if($varhead->title=='welcome')echo 'HomePage';
}
//这是一个类外函数,　我想调类varhead的成员变量title的值.
//但是没想到,　在函数isHome中怎么也得不到$varhead->title的值.
//我开始意识到,　在类外函数中,　可能不能直接调用类的成员变量
//我试过这样,　但仍然不行：
/*
$t=$varhead->title;
function isHome(){
if($t=='welcome')echo 'HomePage';
}
*/
?>

function isHome(){
$varhead1=new varhead();
if($varhead1->title=='welcome')echo 'HomePage';
}

$varhead->setTitle("products");

function isHome(){
global $varhead;
if($varhead->title=='welcome')echo 'HomePage';
}