Introduction to PHP

PHP is a server-side scripting language that is easy to learn and use. With minimal programming knowledge you can use PHP to create a truly interactive web site. This tutorial does not want you to fully understand the language, only to enable you to join the development of dynamic Web sites as soon as possible. I assume you have some basic knowledge of HTML (or HTML editors) and some programming ideas.

1. Introduction

PHP is one of the tools that will allow you to generate dynamic Web pages. PHP Web files are treated as generic HTML Web pages, and you can write PHP in the normal way you edit HTML.

PHP representative: Hypertext Preprocessor (Php:hypertext preprocessor). PHP is completely free, and you can download it free from the official PHP site (http://www.php.net) without spending money. PHP complies with the GNU Public License (GPL), under which many popular software such as Linux and Emacs are born. You can gain unlimited access to the source code, and even add the features you need to yourself. PHP can be run on most Unix platforms, Gun/linux and Microsoft Windows platforms. How to install PHP on a PC machine or UNIX machine on a Windows environment can be found on the PHP website. The installation process is simple.


If your machine solves 2000 problems, then PHP has no bug problem!

1.1 History

Three years ago, Rasmus Lerdorf created the Personal homepage tool (Personal home page tools) to create his online resume. This is a very simple language. Subsequently, more and more people took note of the language and made various suggestions for its expansion. In the selfless devotion of many people and the free nature of the source code of the language itself, it evolves into a rich language, and it is still growing.

Although PHP is easy to learn, it is slower than Mod_perl (The Perl module that is implanted into the Web server). Now there is a new engine called Zend that can be compared to the mod_perl speed, and PHP4 can take advantage of the engine. PHP4 is still in beta testing stage. Andy Gutmans and Zeev Suraki are the main authors of Zend. You can go to the Zend site (http://www.zend.com) to learn more.

PHP's application has grown significantly in personal web projects. According to Netcraft's October 1999 report, there are 931,122 domains and 321,128 IP addresses using PHP technology.

1.2 PHP's Advanced Place

There are many benefits to applying PHP. Of course the known disadvantage is that PHP, because it is an Open-source project, has little business support, and the resulting slow execution rate (until PHP4). But the PHP mailing list is very useful and unless you're running a very popular site like Yahoo! or Amazon.com, you won't be able to feel the speed of PHP different from any other. At least I don't feel it! Well, let's look at the benefits of PHP:

-Learning process


I personally prefer PHP's very simple learning process. Unlike Java and Perl, you don't have to bury your head in more than 100 pages of documents and work hard to write a decent program. Just learn some basic syntax and language features and you can start your PHP coding trip. After that, if you have any trouble with the coding process, you can also read the relevant documents.

PHP syntax with c,perl,asp or JSP. For those who are familiar with one of the above languages, PHP is too simple. On the contrary, if you know more about PHP, you will be easy to learn about several other languages.

You'll only need 30 minutes to master all of the core language features of PHP, you may already know the HTML very well, even if you've already learned how to use editing software or hand-crafted Web sites. Because the PHP code can be easily added to your site, you can design and maintain the site at the same time, you will be very easy to join PHP to make your site more dynamic characteristics.

-Database connection

PHP can be compiled into functions that have connections to many databases. PHP and MySQL are now the perfect combination. You can also write your own peripheral functions to access the database indirectly. This way you can easily change the encoding to accommodate this change when you replace the database you are using. Phplib is the most common set of base libraries that can provide general transaction needs.

-Scalability

As I said before, PHP has entered a period of rapid development. It may be difficult for a programmer to extend additional functionality for PHP, but it is not difficult for a PHP programmer.

-Object Oriented Programming

PHP provides classes and objects. Web-based programming is a great need for object-oriented programming capabilities. PHP supports constructors, extraction classes, and so on.

-Scalability

Traditionally, the interaction of Web pages is achieved through CGI. The CGI program's scalability is not ideal because it runs a separate process for every CGI program that is running. The solution is to compile the interpreter for the language that is often used to write CGI programs into your Web server (such as mod_perl,jsp). PHP can be installed in this way, although few people would like to install it in a CGI way. Embedded PHP can have a higher scalability.

-More Features

In order to be more suitable for web programming, PHP developers have developed many of the popular base libraries around the periphery, which contain more easily available layers. You can use PHP to connect most databases, including Oracle,ms-access,mysql. You can paint on flies, write programs to download or display e-mail. You can even complete network-related functions. Best of all, you can choose which features you need for your PHP installation version. The quote from Nissan's Xterra is that PHP can do what you want it to do and do everything!

1.3 Competitors: asp,mod_perl,jsp

Of course I don't know what asp/jsp can do. But it's clear how easy it is to write code like that, how expensive it is to buy them, and how expensive and powerful hardware they need. If you have any neutral points of view (such as not affected by the million dollars of Sun and Microsoft), please let me know.

As far as I know, JSP is based on Java, so Java programmers can easily start coding. ASP is just a generic engine with the ability to support multiple languages, but the default and most commonly used is VBScript.

Mod_perl is as powerful as Perl, just a little faster.