<?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);

./configure.py
 
make
 
sudo make install

<form action="www.google.com">
<input type="text" name="property" />
<input name="submit" value="submit" type=submit />
<input type="button" value="sub" onclick="javascript:this.form.submit()" />
</form>

<?php
$var = 1;
function(){
    global $var;
    echo $var;
}
?>

var = 1
 
def foo():
    print var

var = 1
 
def foo():
    global var
    var = var + 1
    print var

/**
 * @Author: pwwang(pwwang@pwwang.com)
 * @Function: make a more elegant way to write OO-JavaScript
 * @Note: presevered member name: 
 *   _init -> constructor, 
 *   _super -> super class which this class inherited.
 **/
 
(function($){
 
    $.Class = function(opts, ext){
        //deepcopy, opts won't change
        var temp_opts = {};
        $.extend( temp_opts, opts ); 
 
        // temporarily store the super class
        var _super = {}; 
 
        if( ext && $.isFunction(ext) ){
            // deepcopy ext.prototype that it won't change
            var ext_prttype = {};
            $.extend( ext_prttype, ext.prototype );
            // class extension
            $.extend( ext_prttype, temp_opts);
            // give it back to temp_opts
            $.extend( temp_opts, ext_prttype );
            // get ext.prototype store in _super
            $.extend( _super, ext.prototype );
            // initialize this.super
            temp_opts._super = {};
        }
 
        var CLASS = function(){
            var t = this;
            // class initialization
            CLASS.prototype._init.apply(t, arguments);
            // realize this.super, try to apply THIS to the functions.
            for( var k in _super ){
                temp_opts._super[k] = $.isFunction(_super[k]) 
                ? (function(fn){
                    return function(){
                        fn.apply(t, arguments);
                    }
                })(_super[k]) : _super[k];
            }
        };
 
        // set other variables or functions
        $.extend(CLASS.prototype, temp_opts);
 
        // use static impl to set
        CLASS.impl = function(im){
            $.extend(CLASS.prototype, im);
        };
 
        return CLASS;
    };
 
})(jQuery);

<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery.class.js"></script>
<script type="text/javascript">
$(function(){
    var log = function(v){
        (window.console && window.console.log) ? window.console.log(v) : window.alert(v);
    }
 
    var Anim = $.Class({
        _init: function(weight){
            this.weight = weight;
        },
        eat: function(){
            this.weight ++;
        },
        excrete: function(){
            this.weight --;
        },
        getWeight: function(){
            return this.weight;
        }
    });
 
    var Cat = $.Class({
        _init: function(name, weight){ // override
            this.name = name;
            this.weight = weight;
        }
    }, Anim); // Inheritance 
 
    Cat.impl({
        exercise : function(){
            this.weight -= 2;
        },
        eat: function(){
            if( arguments.length ){ // polymorphism
                this.weight += arguments[0];
            } else {
                this._super.eat();
            }
        }
    });
 
    var Dog = $.Class({
        _init: function(name, weight){
            this.name = name;
            this.weight = weight;
        },
        eat: function(){
            this.weight += 2;
        }
    }, Anim);
 
    var myAnim = new Anim(50);
    log(myAnim.getWeight()); // 50
    myAnim.eat();
    log(myAnim.getWeight()); // 51
    myAnim.excrete();
    log(myAnim.getWeight()); // 50
 
    var myCat = new Cat('cat', 50);
    log(myCat.getWeight()); // 50
    myCat.eat();
    log(myCat.getWeight()); // 51
    myCat.eat(2);
    log(myCat.getWeight()); // 53
    myCat.excrete();
    log(myCat.getWeight()); // 52
    myCat.exercise();
    log(myCat.getWeight()); // 50
 
    var myDog = new Dog('dog', 50);
    log(myDog.getWeight()); // 50
    myDog.eat();
    log(myDog.getWeight()); // 52
    myDog.excrete();
    log(myDog.getWeight()); // 51
 
 
});
</script>
</head>
<body>
</body>
</html>

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

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

<tag />

<html>
<head>
<script src="js/jquery.js"></script>
<script src="js/jquery.tip.js"></script>
<script>
$(function(){
    $('div').tip('This is a multipul style tip. I\'m <font style="font-weight:bold">bold</font>.<br />Line break. I\'m <font style="color:red">red</font>. Images are also availale. <br /> <img src="http://pwwang.com/logo.gif" >');
});
</script>
</head>
<body>
<div style="float:left; width:300px; height:300px; background:#f90;">handler</div>
</body>
</html>

(function($) {
 
    $.tip = function(src, content, cls) {
 
        var $tdiv = $('<div />');
        $tdiv.css({
            'position':'absolute',
            'display':'none',
            'z-index':'9999'
        }).html(content).appendTo('body');
 
        if( cls ){
            $tdiv.addClass(cls);
        } else {
            $tdiv.css({
                'border' : '1px solid #969696',
                'background' : '#ffe',
                'font-size' : '12px',
                'padding' : '2px'
            });
        }
 
        var move = function(e){
            $tdiv.css({
                'top' : (e.pageY+23) + 'px',
                'left' : (e.pageX) + 'px'
            });
        };
 
        $(src).mouseenter(function(e){
            $tdiv.show();
            $(document).bind('mousemove', move);
        });
 
        $(src).mouseleave(function(){
            $tdiv.hide();
            $(document).unbind('mousemove', move);
        });
 
    }
 
    // content: what is the tip
    // cls: the style class of the tip div
    $.fn.tip = function(content, cls) {
 
        this.each(function() {
            new $.tip(this, content, cls);
        });
        return this;    
    };
})(jQuery);