PHP Programming Language: 10 Things You May Not Know_PHP Tutorial

The editor has previously reported on several essential points that PHP developers tend to overlook. In addition to some essential technical methods, there are many subtleties that programmers tend to overlook. Below we have summarized 10 things about PHP that you may not know. things.

For more information about PHP, please visit: Introduction to PHP Development Basics

　 1. Use the ip2long() and long2ip() functions to convert the IP address into an integer Store in database.
This method reduces the storage space to nearly a quarter (15 bytes of char(15) vs. 4 bytes of integer), and calculates whether a specific address is in a Pages within sections are simpler and make searching and sorting faster (although sometimes just a little faster).

　2. Use the checkdnsrr() function to verify whether the domain name exists when verifying the email address.
This built-in function can confirm that the specified domain name can be resolved into an IP address. The user comments section of the PHP documentation for this function has a simple user-defined function based on checkdnsrr() that verifies the validity of the email address. This method can easily catch those who think their email address is memory@wwwphp100.net instead of memory@php100.net.

　3. If you are using PHP 5 and MySQL 4.1 or higher, consider using the mysqli_* series of functions.
A nice feature is that you can use prepared statements, which can speed up queries if you are maintaining a database-intensive site. Some assessment scores.

　4. Learn to fall in love with the ternary operator.

5. If you feel that there are reusable parts in the project, check to see if there is already one in PEAR before you write a line of code.
Many PHP programmers know that PEAR is a good resource library, although many programmers do not know it. This online resource library contains over 400 reusable program snippets that you can use immediately in your programs. Unless your project is really special, you can always find a PEAR package to save you time.

　6. Use highlight_file() to automatically print out beautifully formatted source code.
If you seek help with a script on message boards, IRC, etc., this function is very easy to use. Of course, be careful not to accidentally reveal your database connection information, passwords, etc.

　7. Use the error_reporting(0) function to prevent users from seeing potentially sensitive error information.
Ideally, publishing servers should be completely disabled in php.ini. But if you are using a shared web server and you do not have your own php.ini file, then your best option in this case is to add error_reporting(0);(or using require_once() method). This completely blocks sensitive SQL queries and pathnames in the event of an error.

　8. Use gzcompress() and gzuncompress() to explicitly compress/decompress strings before storing large strings in the database.
This PHP built-in function uses the gzip algorithm, which can compress ordinary text by up to 90%. I use these functions every time I want to read and write BLOB type fields. The only exception is when I need full text search.

　9. Get multiple return values ​​from a function by passing parameters by "reference".
Like the ternary operator, most programmers with formal programming training know this trick. But those programmers whose HTML background is greater than Pascal's background have more or less asked this question "How to return multiple values ​​​​from a function when return can only be used once?" The answer is to add a before the variable. "&" symbol, passing by "reference" instead of "value".

　10. Fully understand the dangers of "magic quotes" and SQL injection.
I hope that the developers reading this already have a good understanding of SQL injection. But I still list this here because it is indeed a bit difficult to understand.

http://www.bkjia.com/PHPjc/486233.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/486233.htmlTechArticleThe editor has previously reported on several essential points that PHP developers tend to overlook. In addition to some essential technical methods, Many subtleties are easily overlooked by programmers. Below we summarize it for you...