Detailed Analysis of PHP Language Defects_PHP Tutorial

PHP language defect 1. Poor support for recursion

Recursion is a mechanism for functions to call themselves. This is a powerful feature that can turn something complex into something very simple. An example of using recursion is quicksort. Unfortunately, PHP is not very good at recursion. Zeev, a PHP developer, said: "PHP 4.0 (Zend) uses a stack approach for dense data rather than a heap approach. This means that the limit on the number of recursive functions it can tolerate is significantly smaller than other languages." See bug 1901. This is a very bad excuse. Every programming language should provide good recursion support.

PHP Language Flaw 2. Many PHP modules are not thread-safe

A few years ago, Apache released version 2.0 of the web server. This version supports multi-threading mode, in which one part of the software can run multiple parts at the same time. The inventor of PHP says that the core of PHP is thread-safe, but non-core modules may not be. But nine times out of ten, you want to use this module in a PHP script, but this makes your script incompatible with Apache's multi-threaded mode. This is why the PHP team does not recommend running PHP in Apache 2's multi-threaded mode. PHP's poor multi-threaded mode support is often cited as one of the reasons why Apache 2 remains unpopular.

PHP language defect 3. PHP is not sound due to business reasons

By using cache, the performance of PHP can be increased by 500% [see benchmark test]. So why isn't caching built into PHP? Because Zend, the maker of PHP, sells its own Zend Accelerator, so of course, they don't want to ditch their commercial product.

But there is another alternative: APC. (Zend later launched Zend Optimizer, a free accelerator - Translator)

PHP language defect 4. No namespace

Imagine someone making a PHP module for reading files. One function in the module is called read. Then another person's module can read the web page, which also contains a function read. Then we can't use these two modules at the same time, because PHP doesn't know which function you want to use. But there is a very simple solution, and that is namespaces. Someone once suggested adding this feature to PHP5, but unfortunately he did not do so. Now, without namespaces, each function must be prefixed with the module name to avoid name conflicts. This results in horribly long function names, such as xsl_xsltprocessor_transform_to_XML, which makes the code difficult to write and understand.

PHP language defect 5. Non-standard date format characters

Many programmers are familiar with date format characters, which come from UNIX and C languages . Several other programming languages ​​have adopted this standard, but strangely enough, PHP has its own set of completely incompatible date format characters. In C, "%j" represents the day of the year, and in PHP it represents the day of the month. However, to make things even more confusing: Smarty (a popular PHP template engine)'s strftime function and date_format function use C/UNIX formatting characters.

PHP Language Defect 6. Confusing License

You may think that PHP is free, and all PHP modules mentioned in the manual are also free. Wrong! For example, if you want to generate PDF files in PHP, you will find two modules in the manual: PDF and ClibPDF. But both of these are commercially licensed. So, for every module you use, you have to make sure you agree to its license.

PHP language defect 7. Inconsistent function naming rules

Some function names are composed of multiple words. There are generally three habits of word combinations:

Direct splicing: getnumberoffiles

Separated by underscores: get_number_of_files

Camel’s rule: getNumberOfFiles

Most languages ​​choose among them. One middle school. But PHP is used.

For example, if you want to convert some special characters into HTML entities, you would use the function htmlentities (directly splicing words). If you want to use the opposite functionality, you need to use its little brother html_entity_decode. For some special reason, this function name has words separated by underscores. How can this be? You know there is a function called strpad. Or is it str_pad? Every time you have to check what the symbol is or just wait for an error. Functions are case-insensitive, so for PHP there is no difference between rawurldecode and RawUrlDecode. This is also bad because both are used and they look different, confusing the reader.

PHP language defect 8. The hell of magic quotes

Magic quote can protect PHP scripts from SQL injection attacks. This is good. But for some reasons, you can turn off this configuration in php.ini. So if you want to write a flexible script, you always need to check whether magic references are on or off. Such a "feature" is supposed to make programming easier, but in fact it makes it more complicated.

PHP language defect 9. Lack of standard framework

A growing website without an overall framework will eventually become a maintenance nightmare. A framework can make many tasks easier. The most popular framework model now is the MVC-model, in which the presentation layer, business logic and database access are separated. Many PHP websites do not use the MVC-model. They don't even have a frame. Even now there are some PHP frameworks and you can write one yourself. The articles and manuals about PHP do not improve the framework a word. While JSP-developers use frameworks like Struts and ASP developers use .net, it seems like these concepts are widely understood by PHP developers. This shows how professional PHP actually is.