PHP Tricks help

Choose meaningful variable names and remember they're case-sensitive.
Use comments to remind you what your script does.
Remember that numbers don't require quotes, but strings (text) do.
You can use single or double quotes, but the outer pair must match.
Use a backslash to escape quotes of the same type inside a string.
To store related items together, use an array.
Use conditional statements, such as if and if... else, for decision making.
Simplify repetitive tasks with loops.
Use functions to perform preset tasks.
Display PHP output with echo or print.
Inspect the content of arrays with print_r().
With most error messages, work backward from the position indicated.
Keep smiling—and remember that PHP is not difficult.

THE H1B VISA PROCESS : USA UK CANADA Australia Jobs Search Engine

THE H1B VISA PROCESS :-
to obtain an H1B visa, an applicant must 'first' find an H1B job with an H1B visa employer company in the USA; commonly known as your 'H1B sponsor'.

Your H1B sponsor then applies for / files your H1B visa application. Individuals can NOT sponsor or apply for their own H1B visa - ONLY your new employer (sponsor) can.

An H1B visa is typically valid for up to six (6) years and entitles your spouse (husband/wife) and children to accompany you and 'live' in America.

One of the main advantages of the H1B visa (US work permit) is that it is a 'dual intent' visa which means that you can apply for a Green Card (Legal Permanent Residency).

To obtain an H1B visa to work in the USA....
* the 1st step is that you Must find an H1B Job with an H1B sponsor company.
* Individuals can Not sponsor/apply for your own H1B visa - only your new employer can.

H1B Visa Global Jobs Consultant Search Global jobs online UK USA CANADA and Australia

H-1B visa

http://globaljobsonline.blogspot.com

The US H1B visa is a non-immigrant visa, which allows a US company to employ a foreign individual for up to six years. As applying for a non-immigration visa is generally quicker than applying for a US Green Card, staff required on long-term assignment in the US are often initially brought in using a non-immigrant visa such as the H1B visa.

Individuals can not apply for an H1B visa to allow them to work in the US. The employer must petition for entry of the employee. H1B visas are subject to annual numerical limits.

US employers may begin applying for the H-1B visa six months before the actual start date of the visa. Since the beginning of the FY 2007 is October 1, 2006, employers can apply as soon as April 1, 2006 for the FY 2007 cap, but the beneficiary cannot start work until October 1st.

The H1B visa is designed to be used for staff in "speciality occupations", that is those occupations which require a high degree of specialized knowledge. Generally at least the equivalent of a job-relevant 4-year US Bachelor's degree is required (this requirement can usually be met by having a 3-year degree and 3 years' relevant post-graduate experience). However, professionals such as lawyers, doctors, accountants and others must be licensed to practice in the state of intended employment – e.g. a lawyer must generally have passed the relevant state bar exam.

Non-graduates may be employed on an H1B visa where they can claim to be 'graduate equivalent' by virtue of twelve or more years' experience in the occupation.

Positions that are not "speciality occupations", or for which the candidate lacks the qualifications/experience for an H1B visa, may be filled using an H-2B visa. The disadvantage of the H-2B visa is that it requires 'labor certification' - an expensive and time consuming process that involves extensive advertising of the position, and satisfying the authorities that there are no US workers available to do the job. Also, H-2B visas are initially granted only for one year, extendable in one year increments to a maximum of 3 years. As each extension requires a new Labor Certification, it unsurprising that, of the annual quota of 66,000 H-2B visas, only a few thousand are ever issued.

New H1B legislation requires certain employers, called 'H1B dependent employers' to advertise positions in the USA before petitioning to employ H1B workers for those positions. H1B dependent employers are defined as those having more than 15% of their employees in H1B status (for firms with over 50 employees – small firms are allowed a higher percentage of H1B employees before becoming 'dependent'). In addition all new H1B petitions and 1^st extensions of H1B's now require a fee (in addition to the usual filing fees) of US$1,000 to be paid, which will be used to fund a training programme for resident US workers.

The initial visa may be granted for up to three years. It may then be extended, in the first instance for up to two further years, and eventually for one further year, to a maximum of six years. Those wishing to remain in the US for more than six years may, while still in the US on an H1B visa, apply for permanent residence (the "green card"): if such employees do not gain permanent residence, when the six year period runs out, they must live outside the US for at least one year before an application is made for them to enter on an H or an L visa.

Once a company has brought an employee to the US on an H1B visa, should the company dismiss that employee before the expiry of the visa, the company is liable for any reasonable costs that the employee incurs in moving him/herself, his/her effects, back to his/her last foreign residence. This provision covers only dismissal, it is not relevant when an employee chooses to resign.

Polymorphism PHP Mysql

Polymorphism

The database wrappers developed in this chapter are pretty generic. In fact, if you look at the other database extensions built in to PHP, you see the same basic functionality over and over againconnecting to a database, preparing queries, executing queries, and fetching back the results. If you wanted to, you could write a similar DB_Pgsql or DB_Oracle class that wraps the PostgreSQL or Oracle libraries, and you would have basically the same methods in it.

In fact, although having basically the same methods does not buy you anything, having identically named methods to perform the same sorts of tasks is important. It allows for polymorphism, which is the ability to transparently replace one object with another if their access APIs are the same.

In practical terms, polymorphism means that you can write functions like this:

function show_entry($entry_id, $dbh)
{
  $query = "SELECT * FROM Entries WHERE entry_id = :1";
  $stmt = $dbh->prepare($query)->execute($entry_id);
  $entry = $stmt->fetch_row(); 
  // display entry
}

This function not only works if $dbh is a DB_Mysql object, but it works fine as long as $dbh implements a prepare() method and that method returns an object that implements the execute() and fetch_assoc() methods.

To avoid passing a database object into every function called, you can use the concept of delegation. Delegation is an OO pattern whereby an object has as an attribute another object that it uses to perform certain tasks.

The database wrapper libraries are a perfect example of a class that is often delegated to. In a common application, many classes need to perform database operations. The classes have two options:

• You can implement all their database calls natively. This is silly. It makes all the work you've done in putting together a database wrapper pointless.

• You can use the database wrapper API but instantiate objects on-the-fly. Here is an example that uses this option:

  class Weblog {
    public function show_entry($entry_id)
    {
      $query = "SELECT * FROM Entries WHERE entry_id = :1";
      $dbh = new Mysql_Weblog(); 
      $stmt = $dbh->prepare($query)->execute($entry_id);
      $entry = $stmt->fetch_row();
      // display entry
    }
  }
  

  
  

  On the surface, instantiating database connection objects on-the-fly seems like a fine idea; you are using the wrapper library, so all is good. The problem is that if you need to switch the database this class uses, you need to go through and change every function in which a connection is made.

• You implement delegation by having Weblog contain a database wrapper object as an attribute of the class. When an instance of the class is instantiated, it creates a database wrapper object that it will use for all input/output (I/O). Here is a re-implementation of Weblog that uses this technique:

  class Weblog {
    protected $dbh;
    public function setDB($dbh)
    {
      $this->dbh = $dbh;
    }
    public function show_entry($entry_id)
    {
      $query = "SELECT * FROM Entries WHERE entry_id = :1"; 
      $stmt = $this->dbh->prepare($query)->execute($entry_id);
      $entry = $stmt->fetch_row();
      // display entry
    }
  }
  

  
  

Now you can set the database for your object, as follows:

$blog = new Weblog;
$dbh = new Mysql_Weblog;
$blog->setDB($dbh);

Of course, you can also opt to use a Template pattern instead to set your database delegate:

class Weblog_Std extends Weblog {
  protected $dbh;
  public function _ _construct()
  {
    $this->dbh = new Mysql_Weblog;
  }
}
$blog = new Weblog_Std;
 

Delegation is useful any time you need to perform a complex service or a service that is likely to vary inside a class. Another place that delegation is commonly used is in classes that need to generate output. If the output might be rendered in a number of possible ways (for example, HTML, RSS [which stands for Rich Site Summary or Really Simple Syndication, depending on who you ask], or plain text), it might make sense to register a delegate capable of generating the output that you want.

The Template Pattern - PHP Mysql Class

The Template Pattern

The Template pattern describes a class that modifies the logic of a subclass to make it complete.

You can use the Template pattern to hide all the database-specific connection parameters in the previous classes from yourself. To use the class from the preceding section, you need to constantly specify the connection parameters:

<?php
require_once 'DB.inc';

define('DB_MYSQL_PROD_USER', 'test');
define('DB_MYSQL_PROD_PASS', 'test');
define('DB_MYSQL_PROD_DBHOST', 'localhost'); 
define('DB_MYSQL_PROD_DBNAME', 'test');

$dbh = new DB::Mysql(DB_MYSQL_PROD_USER, DB_MYSQL_PROD_PASS,
                     DB_MYSQL_PROD_DBHOST, DB_MYSQL_PROD_DBNAME);
$stmt = $dbh->execute("SELECT now()"); 
print_r($stmt->fetch_row());
?>

To avoid having to constantly specify your connection parameters, you can subclass DB_Mysql and hard-code the connection parameters for the test database:

class DB_Mysql_Test extends DB_Mysql {
  protected $user   = "testuser";
  protected $pass   = "testpass";
  protected $dbhost = "localhost"; 
  protected $dbname = "test";

  public function _ _construct() { }
}

Similarly, you can do the same thing for the production instance:

class DB_Mysql_Prod extends DB_Mysql {
  protected $user   = "produser";
  protected $pass   = "prodpass";
  protected $dbhost = "prod.db.example.com ";
  protected $dbname = "prod";

  public function _ _construct() { }
}

Mysql Query Class - PHP OOP Method

Versions of MySQL prior to 4.1 do not provide a separate interface for users to prepare queries prior to execution or allow bind SQL. For us, though, passing all the variable data into the process separately provides a convenient place to intercept the variables and escape them before they are inserted into the query. An interface to the new MySQL 4.1 functionality is provided through Georg Richter's mysqli extension.

To accomplish this, you need to modify DB_Mysql to include a prepare method and DB_MysqlStatement to include bind and execute methods:

class DB_Mysql {
  /* ... */
  public function prepare($query) {
    if(!$this->dbh) {
      $this->connect();
    }
    return new DB_MysqlStatement($this->dbh, $query); 
  }
}
class DB_MysqlStatement {
  public $result;
  public $binds;
  public $query;
  public $dbh;
  /* ... */
  public function execute() {
    $binds = func_get_args();
    foreach($binds as $index => $name) { 
      $this->binds[$index + 1] = $name;
    }
    $cnt = count($binds);
    $query = $this->query;
    foreach ($this->binds as $ph => $pv) {
      $query = str_replace(":$ph", "'".mysql_escape_string($pv)."'", $query); 
    }
    $this->result = mysql_query($query, $this->dbh);
    if(!$this->result) {
      throw new MysqlException;
    }
    return $this;
  }
  /* ... */
}

In this case, prepare() actually does almost nothing; it simply instantiates a new DB_MysqlStatement object with the query specified. The real work all happens in DB_MysqlStatement. If you have no bind parameters, you can just call this:

$dbh = new DB_Mysql("testuser", "testpass", "localhost", "testdb");
$stmt = $dbh->prepare("SELECT *
                       FROM users
                       WHERE name = '".mysql_escape_string($name)."'"); 
$stmt->execute();

The real benefit of using this wrapper class rather than using the native procedural calls comes when you want to bind parameters into your query. To do this, you can embed placeholders in your query, starting with :, which you can bind into at execution time:

$dbh = new DB_Mysql("testuser", "testpass",
"localhost", "testdb");
$stmt = $dbh->prepare("SELECT * FROM users WHERE name = :1"); 
$stmt->execute($name);

The :1 in the query says that this is the location of the first bind variable. When you call the execute() method of $stmt, execute() parses its argument, assigns its first passed argument ($name) to be the first bind variable's value, escapes and quotes it, and then substitutes it for the first bind placeholder :1 in the query.

Even though this bind interface doesn't have the traditional performance benefits of a bind interface, it provides a convenient way to automatically escape all input to a query.

PHP Mysql Class

The Adaptor Pattern

The Adaptor pattern is used to provide access to an object via a specific interface. In a purely OO language, the Adaptor pattern specifically addresses providing an alternative API to an object; but in PHP we most often see this pattern as providing an alternative interface to a set of procedural routines.

Providing the ability to interface with a class via a specific API can be helpful for two main reasons:

• If multiple classes providing similar services implement the same API, you can switch between them at runtime. This is known as polymorphism. This is derived from Greek: Poly means "many," and morph means "form."

• A predefined framework for acting on a set of objects may be difficult to change. When incorporating a third-party class that does not comply with the API used by the framework, it is often easiest to use an Adaptor to provide access via the expected API.

The most common use of adaptors in PHP is not for providing an alternative interface to one class via another (because there is a limited amount of commercial PHP code, and open code can have its interface changed directly). PHP has its roots in being a procedural language; therefore, most of the built-in PHP functions are procedural in nature. When functions need to be accessed sequentially (for example, when you're making a database query, you need to use mysql_pconnect(), mysql_select_db(), mysql_query(), and mysql_fetch()), a resource is commonly used to hold the connection data, and you pass that into all your functions. Wrapping this entire process in a class can help hide much of the repetitive work and error handling that need to be done.

The idea is to wrap an object interface around the two principal MySQL extension resources: the connection resource and the result resource. The goal is not to write a true abstraction but to simply provide enough wrapper code that you can access all the MySQL extension functions in an OO way and add a bit of additional convenience. Here is a first attempt at such a wrapper class:

class DB_Mysql {
  protected $user;
  protected $pass;
  protected $dbhost;
  protected $dbname;
  protected $dbh;    // Database connection handle 

  public function _ _construct($user, $pass, $dbhost, $dbname) {
    $this->user = $user;
    $this->pass = $pass;
    $this->dbhost = $dbhost;
    $this->dbname = $dbname;
  }
  protected function connect() { 
    $this->dbh = mysql_pconnect($this->dbhost, $this->user, $this->pass);
    if(!is_resource($this->dbh)) {
      throw new Exception;
    }
    if(!mysql_select_db($this->dbname, $this->dbh)) { 
      throw new Exception;
    }
  }
  public function execute($query) {
    if(!$this->dbh) {
      $this->connect();
    }
    $ret = mysql_query($query, $this->dbh);
    if(!$ret) { 
      throw new Exception;
    }
    else if(!is_resource($ret)) {
      return TRUE;
    } else {
      $stmt = new DB_MysqlStatement($this->dbh, $query);
      $stmt->result = $ret;
      return $stmt; 
    }
  }
}

To use this interface, you just create a new DB_Mysql object and instantiate it with the login credentials for the MySQL database you are logging in to (username, password, hostname, and database name):

$dbh = new DB_Mysql("testuser", "testpass", "localhost", "testdb");
$query = "SELECT * FROM users WHERE name = '".mysql_escape_string($name)."'"; 
$stmt = $dbh->execute($query);

This code returns a DB_MysqlStatement object, which is a wrapper you implement around the MySQL return value resource:

class DB_MysqlStatement {
  protected $result;
  public $query;
  protected $dbh;
  public function _ _construct($dbh, $query) {
    $this->query = $query; 
    $this->dbh = $dbh;
    if(!is_resource($dbh)) {
      throw new Exception("Not a valid database connection");
    }
  }
  public function fetch_row() {
    if(!$this->result) {
       throw new Exception("Query not executed");
    }
    return mysql_fetch_row($this->result);
  }
  public function fetch_assoc() {
    return mysql_fetch_assoc($this->result);
  }
   public function fetchall_assoc() {
    $retval = array();
    while($row = $this->fetch_assoc()) {
      $retval[] = $row;
    }
    return $retval;
  }
}

To then extract rows from the query as you would by using mysql_fetch_assoc(), you can use this:

while($row = $stmt->fetch_assoc()) {
  // process row
}

PHP - A Brief Introduction to Design Patterns PHP Certification Free Tutorials

You have likely heard of design patterns, but you might not know what they are. Design patterns are generalized solutions to classes of problems that software developers encounter frequently. If you've programmed for a long time, you have most likely needed to adapt a library to be accessible via an alternative API. You're not alone. This is a common problem, and although there is not a general solution that solves all such problems, people have recognized this type of problem and its varying solutions as being recurrent. The fundamental idea of design patterns is that problems and their corresponding solutions tend to follow repeatable patterns. Design patterns suffer greatly from being overhyped. For years I dismissed design patterns without real consideration. My problems were unique and complex, I thoughtthey would not fit a mold. This was really short-sighted of me. Design patterns provide a vocabulary for identification and classification of problems. In Egyptian mythology, deities and other entities had secret names, and if you could discover those names, you could control the deities' and entities' power. Design problems are very similar in nature. If you can discern a problem's true nature and associate it with a known set of analogous (solved) problems, you are most of the way to solving it. To claim that a single chapter on design patterns is in any way complete would be ridiculous. The following sections explore a few patterns, mainly as a vehicle for showcasing some of the advanced OO techniques available in PHP.

PHP Class Overview Learn PHP Easy - Tutorials Globaljobsonline.blogspot.com

Introduction to OO Programming

It is important to note that in procedural programming, the functions and the data are separated from one another. In OO programming, data and the functions to manipulate the data are tied together in objects. Objects contain both data (called attributes or properties) and functions to manipulate that data (called methods).

An object is defined by the class of which it is an instance. A class defines the attributes that an object has, as well as the methods it may employ. You create an object by instantiating a class. Instantiation creates a new object, initializes all its attributes, and calls its constructor, which is a function that performs any setup operations. A class constructor in PHP5 should be named __construct() so that the engine knows how to identify it. The following example creates a simple class named User, instantiates it, and calls its two methods:

<?php
class User {
  public $name;
  public $birthday;
  public function __construct($name, $birthday)
  {
    $this->name = $name;
    $this->birthday = $birthday; 
  }
  public function hello()
  {
    return "Hello $this->name!\n";
  }
  public function goodbye()
  {
    return "Goodbye $this->name!\n";
  }
  public function age() { 
    $ts = strtotime($this->birthday);
    if($ts === -1) {
      return "Unknown";
    }
    else {
      $diff = time() - $ts;
      return floor($diff/(24*60*60*365)) ;
    }
  } 
}
$user = new User('george', '10 Oct 1973');
print $user->hello();
print "You are ".$user->age()." years old.\n";
print $user->goodbye();
?>

Running this causes the following to appear:

Hello george!
You are 29 years old.
Goodbye george!

The constructor in this example is extremely basic; it only initializes two attributes, name and birthday. The methods are also simple. Notice that $this is automatically created inside the class methods, and it represents the User object. To access a property or method, you use the -> notation.

On the surface, an object doesn't seem too different from an associative array and a collection of functions that act on it. There are some important additional properties, though, as described in the following sections:

• Inheritance Inheritance is the ability to derive new classes from existing ones and inherit or override their attributes and methods.

• Encapsulation Encapsulation is the ability to hide data from users of the class.

• Special Methods As shown earlier in this section, classes allow for constructors that can perform setup work (such as initializing attributes) whenever a new object is created. They have other event callbacks that are triggered on other common events as well: on copy, on destruction, and so on.

• Polymorphism When two classes implement the same external methods, they should be able to be used interchangeably in functions. Because fully understanding polymorphism requires a larger knowledge base than you currently have, we'll put off discussion of it until later in this chapter, in the section "Polymorphism."

Inheritance

You use inheritance when you want to create a new class that has properties or behaviors similar to those of an existing class. To provide inheritance, PHP supports the ability for a class to extend an existing class. When you extend a class, the new class inherits all the properties and methods of the parent (with a couple exceptions, as described later in this chapter). You can both add new methods and properties and override the exiting ones. An inheritance relationship is defined with the word extends. Let's extend User to make a new class representing users with administrative privileges. We will augment the class by selecting the user's password from an NDBM file and providing a comparison function to compare the user's password with the password the user supplies:

class AdminUser extends User{
  public $password;
  public function _ _construct($name, $birthday)
  {
    parent::_ _construct($name, $birthday); 
    $db = dba_popen("/data/etc/auth.pw", "r", "ndbm");
    $this->password = dba_fetch($db, $name);
    dba_close($db);
  }
  public function authenticate($suppliedPassword) 
  {
    if($this->password === $suppliedPassword) {
      return true;
    }
    else {
      return false;
    }
  }
}

Although it is quite short, AdminUser automatically inherits all the methods from User, so you can call hello(), goodbye(), and age(). Notice that you must manually call the constructor of the parent class as parent::_ _constructor(); PHP5 does not automatically call parent constructors. parent is as keyword that resolves to a class's parent class.

Encapsulation

Users coming from a procedural language or PHP4 might wonder what all the public stuff floating around is. Version 5 of PHP provides data-hiding capabilities with public, protected, and private data attributes and methods. These are commonly referred to as PPP (for public, protected, private) and carry the standard semantics:

• Public A public variable or method can be accessed directly by any user of the class.

• Protected A protected variable or method cannot be accessed by users of the class but can be accessed inside a subclass that inherits from the class.

• Private A private variable or method can only be accessed internally from the class in which it is defined. This means that a private variable or method cannot be called from a child that extends the class.

Encapsulation allows you to define a public interface that regulates the ways in which users can interact with a class. You can refactor, or alter, methods that aren't public, without worrying about breaking code that depends on the class. You can refactor private methods with impunity. The refactoring of protected methods requires more care, to avoid breaking the classes' subclasses.

Encapsulation is not necessary in PHP (if it is omitted, methods and properties are assumed to be public), but it should be used when possible. Even in a single-programmer environment, and especially in team environments, the temptation to avoid the public interface of an object and take a shortcut by using supposedly internal methods is very high. This quickly leads to unmaintainable code, though, because instead of a simple public interface having to be consistent, all the methods in a class are unable to be refactored for fear of causing a bug in a class that uses that method. Using PPP binds you to this agreement and ensures that only public methods are used by external code, regardless of the temptation to shortcut.

Static (or Class) Attributes and Methods

In addition, methods and properties in PHP can also be declared static. A static method is bound to a class, rather than an instance of the class (a.k.a., an object). Static methods are called using the syntax ClassName::method(). Inside static methods, $this is not available.

A static property is a class variable that is associated with the class, rather than with an instance of the class. This means that when it is changed, its change is reflected in all instances of the class. Static properties are declared with the static keyword and are accessed via the syntax ClassName::$property. The following example illustrates how static properties work:

class TestClass {
  public static $counter;
}
$counter = TestClass::$counter;

If you need to access a static property inside a class, you can also use the magic keywords self and parent, which resolve to the current class and the parent of the current class, respectively. Using self and parent allows you to avoid having to explicitly reference the class by name. Here is a simple example that uses a static property to assign a unique integer ID to every instance of the class:

class TestClass {
  public static $counter = 0;
  public $id;

  public function _ _construct()
  {
    $this->id = self::$counter++;
  }
}

Special Methods

Classes in PHP reserve certain method names as special callbacks to handle certain events. You have already seen _ _construct(), which is automatically called when an object is instantiated. Five other special callbacks are used by classes: _ _get(), _ _set(), and _ _call() influence the way that class properties and methods are called, and they are covered later in this chapter. The other two are _ _destruct() and _ _clone().

_ _destruct() is the callback for object destruction. Destructors are useful for closing resources (such as file handles or database connections) that a class creates. In PHP, variables are reference counted. When a variable's reference count drops to 0, the variable is removed from the system by the garbage collector. If this variable is an object, its _ _destruct() method is called.

The following small wrapper of the PHP file utilities showcases destructors:

class IO {
  public $fh = false;
  public function _ _construct($filename, $flags)
  {
    $this->fh = fopen($filename, $flags);
  }
  public function _ _destruct()
  {
    if($this->fh) { 
      fclose($this->fh);
    }
  }
  public function read($length)
  {
    if($this->fh) {
      return fread($this->fh, $length);
    }
  }
  /* ... */
}

In most cases, creating a destructor is not necessary because PHP cleans up resources at the end of a request. For long-running scripts or scripts that open a large number of files, aggressive resource cleanup is important.

In PHP4, objects are all passed by value. This meant that if you performed the following in PHP4:

$obj = new TestClass;
$copy = $obj;

you would actually create three copies of the class: one in the constructor, one during the assignment of the return value from the constructor to $copy, and one when you assign $obj to $copy. These semantics are completely different from the semantics in most other OO languages, so they have been abandoned in PHP5.

In PHP5, when you create an object, you are returned a handle to that object, which is similar in concept to a reference in C++. When you execute the preceding code under PHP5, you only create a single instance of the object; no copies are made.

To actually copy an object in PHP5, you need to use the built-in _ _clone() method. In the preceding example, to make $copy an actual copy of $obj (and not just another reference to a single object), you need to do this:

$obj = new TestClass;
$copy = $obj->_ _clone();

For some classes, the built-in deep-copy _ _clone() method may not be adequate for your needs, so PHP allows you to override it. Inside the _ _clone() method, you have $this, which is the new object with all the original object's properties already copied. For example, in the TestClass class defined previously in this chapter, if you use the default _ _clone() method, you will copy its id property. Instead, you should rewrite the class as follows:

class TestClass {
  public static $counter = 0;
  public $id;
  public $other;

  public  function _ _construct()
  {
    $this->id = self::$counter++; 
  }
  public function _ _clone()
  {
    $this->id = self::$counter++;
  }
}

http://zendphp.blogspot.com/

http://zendexam.blogspot.com/

http://zendcertification.blogspot.com/

PHP - Object-Oriented Programming Through Design Patterns

Object-Oriented Programming Through Design Patterns

BY FAR THE LARGEST AND MOST HERALDED change in PHP5 is the complete revamping of the object model and the greatly improved support for standard object-oriented (OO) methodologies and techniques. This book is not focused on OO programming techniques, nor is it about design patterns. There are a number of excellent texts on both subjects (a list of suggested reading appears at the end of this chapter). Instead, this chapter is an overview of the OO features in PHP5 and of some common design patterns.

I have a rather agnostic view toward OO programming in PHP. For many problems, using OO methods is like using a hammer to kill a fly. The level of abstraction that they offer is unnecessary to handle simple tasks. The more complex the system, though, the more OO methods become a viable candidate for a solution. I have worked on some large architectures that really benefited from the modular design encouraged by OO techniques.

This chapter provides an overview of the advanced OO features now available in PHP. Some of the examples developed here will be used throughout the rest of this book and will hopefully serve as a demonstration that certain problems really benefit from the OO approach.

OO programming represents a paradigm shift from procedural programming, which is the traditional technique for PHP programmers. In procedural programming, you have data (stored in variables) that you pass to functions, which perform operations on the data and may modify it or create new data. A procedural program is traditionally a list of instructions that are followed in order, using control flow statements, functions, and so on. The following is an example of procedural code:

<?php
function hello($name)
{
  return "Hello $name!\n";
}
function goodbye($name)
{
  return "Goodbye $name!\n";
}
function age($birthday) {
  $ts = strtotime($birthday); 
  if($ts === -1) {
    return "Unknown";
  }
  else {
    $diff = time() - $ts;
    return floor($diff/(24*60*60*365));
  }
}
$name = "george";
$bday = "10 Oct 1973"; 
print hello($name);
print "You are ".age($bday)." years old.\n";
print goodbye($name);
? >

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Zend Exam Blogs Tips & Tricks on PHP

NO MATTER WHAT YOUR PROFICIENCY LEVEL in PHP, no matter how familiar you are with the language internals or the idiosyncrasies of various functions or syntaxes, it is easy to write sloppy or obfuscated code. Hard-to-read code is difficult to maintain and debug. Poor coding style connotes a lack of professionalism.

I once inherited a code base of some 200,000 lines, developed by three teams of developers. When we were lucky, a single include would at least be internally consistentbut often a file would manifest three different styles scattered throughout.

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