Php study notes ?? PHP overview

Php study notes ?? PHP Overview 1. PHP

Basic knowledge

PHP

PHP is one of the most popular server-side Web programming languages. PHP features simple syntax.

Easy to Learn, powerful, flexible and easy to use. After integrating some of the best features of modern programming languages, PHP and Apache

The combination with MySQL has become a configuration standard for Web servers. PHP learning is very easy and quick.

. It can be said that PHP has become a pioneer in Web script technology and will continue to lead the trend of Web technology.

PHP, an abbreviated name for nesting, is an English super Text preprocessing language (PHP: Hypertext Preprocessor)

. PHP is an embedded HTML language. PHP is similar to Microsoft's ASP.

Script language for embedding HTML documents on the server. the language style is similar to C.

Website programmers are widely used. The unique PHP syntax combines C, Java, Perl, and PHP self-innovative

Syntax. It can execute dynamic web pages more quickly than CGI or Perl. Dynamic pages made using PHP and other

Compared with programming languages, PHP embeds programs into HTML documents for execution, and the execution efficiency is more efficient than generating HTML labels.

The CGI is much higher. compared with the scripting language JavaScript, which is also embedded in HTML documents

The PHP execution engine also stores frequently accessed PHP programs in

Memory, other users do not need to re-compile the program when accessing this program again, as long as

Code is enough, which is also one of the manifestations of PHP's high efficiency. PHP has very powerful functions, all CGI

Or JavaScript functions can be implemented in PHP, and supports almost all popular databases and operating systems.

PHP was initially created in 1994 by Rasmus Lerdorf. it was just a simple script written in Perl.

The program used to count the visitors to his own website. Later, I wrote it again in C language, including accessing the database.

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Font Capture: invalid rd32info.exe-application error

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"0x00000014" memory referenced by the "0x0700609c" command. The memory cannot be "read ".

Full encryption and Hash Encryption. the encryption algorithms used include Blowfish, MD5, SHA1, and Triple DES.

5. isap I support. ISAPI support allows you to combine PHP with Microsoft's IIS Web server.

6. built-in support for COM/dco m. Another benefit for Windows users is that PHP 4 can access and instantiate COM.

Object. This feature extends the interoperability with Windows applications.

7. built-in Jav a support. This is also a major improvement in PHP interoperability. Version 4.0 supports PHP application binding.

Set Java objects.

8. Regular expression (PCRE) library compatible with Per l. The Perl language has been dominant in the field of string parsing.

Dominant. Developers know that if PHP is to be widely recognized, powerful regular expression functions will play an important role

. Their approach is to integrate the Perl function, rather than re-development, and integrate the PCRE library package into the default release of PHP.

In the package.

In addition to these features, version 4 also adds hundreds of features, greatly improving the ability of this language. In this book, I

We will discuss most of these features.

In the course of PHP language development, PHP 4 represents a huge leap. This new version brings new features and power

The ability and scalability have caused a lot of shock to new developers and veterans. However, the PHP development team is not satisfied

With this achievement, they soon began to undertake another milestone task, to launch a leading Web

Scripting language: PHP 5.

PHP5

Version 5 is another watershed in the development of PHP. Although many libraries have been added in the previous major versions,

Version 5 has made many improvements to the existing functions, and added some unique features of the mature programming language architecture.

.

1. the object-oriented capability is greatly improved. PHP's object-oriented architecture has been improved, which is the most prominent in version 5.

Features. Version 5 adds many functions, such as explicit constructor and Destructor, object cloning, class abstraction, and variable functions.

Domain and interface. In addition, PHP has made significant improvements in object management. Chapter 6th and chapter 7th will detail these

Content.

2. try/catch

Exception handling. It is ironic that, in structured programming languages, the design of error handling policy libraries

It is very error-prone, and it is difficult to maintain consistency. To solve this problem, Version 5 began to support exception handling. In

In many languages, such as C ++, C #, Python, and Java, exception handling has always been an issue of error management.

It provides an excellent way to establish standardized error reporting logic.

3. improved XML

And Web

Service Support. Currently, XML can be built on the libxml2 library.

A new but promising extension package to parse and process XML, SimpleXML. PHP 5 also supports

SOAP extension. Chapter 2 introduces these two new extensions and some great third-party Web service extensions.

4. For SQLite

Built-in support. Developers are always willing to provide more options. they are powerful but concise

The SQLite database server (http://www.sqlite.org/) provides support. If developers need some weight

Only features of database-level products, without the need to bring the corresponding management overhead, SQLite can be these developers

Personnel provide a convenient solution. Chapter 2 describes how PHP supports this powerful database engine.

PHP6

1. Unicode

Yes. Added local Unicode support, making it easy to build and maintain multilingual applications

.

2. security improvement. A lot of security improvements have been made. Based on these improvements, the security phase should be able to be significantly curbed.

To be honest, these problems cannot be attributed to the language, but to the inexperienced programmers who work together.

3. new language features and structures. Many new syntax features are added, the most prominent of which is the 64-bit integer type,

Transformed foreach loop construction for multi-dimensional arrays. And the break support for tags.

II. environment configuration

I used wamp and xampp.

You can download the two software on the Internet.

(The notes are written by instructor Li Yanhui)