PHP5 (1)

Source: Internet
Author: User
Tags exception handling
Although PHP5 has not yet been officially released (the development version has been provided for download), we can now start to experience the surprises that the new version will bring us. In the following introduction, we will focus on three major features in PHP5. These three features are:
* New Object Mode)
* Exception handling)
* Namespace)
Before you begin, you must declare two points:
* The example in this article is to illustrate how to perform the operation. Some parts use the PHP4 expression method, which is only to improve the readability of the article.
* The part described in this article may differ from the final release version of PHP5.
Before the final release of PHP5, you can download the latest build from the http://snaps.php.net at any time to experience the new features that PHP5 brings to us.
New Object Mode
Objects in PHP5 have been adjusted systematically and comprehensively. The current situation may look similar to Java. This section describes the new object mode in PHP5 and provides some simple examples. Let this section be a new starting point for your PHP5 journey. :)
* Constructor and Destructor
* Object reference
* Object cloning
* Private, public, and protected modes in the object
* Interface (Interfaces)
* Abstract class
* _ Call
* _ Set and _ get
* Static members
Constructor and Destructor
In PHP4, when a function has the same name as an object, this function becomes the constructor of the object, and there is no destructor concept in PHP4.
In PHP5, constructor is uniformly named as _ construct, and the concept of destructor is introduced. It is uniformly named as _ destruct.
Example 1: constructor and Destructor
<? Php
Class foo {
Var $ x;
Function _ construct ($ x ){
$ This-> x = $ x;
}
Function display (){
Print ($ this-> x );
}
Function _ destruct (){
Print ("bye ");
}
}
$ O1 = new foo (4 );
$ O1-> display ();
?>
In the above example, when you terminate the call to the foo class, the destructor will be called, and "bye" will be output in the above example ".
Object reference
As we all know, in PHP4, when a variable is passed to a function or method, the variable is actually copied once, which means that you pass a copy of the variable to the function or method, unless you use the reference symbol "&" to declare that you want to make a reference, not a Copy. In PHP5, objects always exist as references, and assignment operations in objects are also a reference operation.
Example 2: Object reference

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