Excerpted from PHP Manual[2] – Overview of Common System Functions

Recently, I systematically read the PHP manual, and now I have reached the core part of the manual, the system function library. This is the essence of the manual. And we don’t need to master all of the huge function library at present. The following is a series of system functions that I think are more commonly used and need to be mastered after browsing them one by one. Please refer to the PHP manual for specific usage.

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Array ##Points##
Classes/Objects
CURL
Date/Time
Directories
Filesystem
FTP
Function Handling
Image
MySQL
MySQLi
Output Control
PCRE - Perl compatible regular expression function
PDO
Sessions
SimpleXML Other related to operating XML
SOAP/socket
Strings ##Key##
URLs
Variables
========== ========

Another thing to note is that just reading the manual is not enough. If you encounter a method that you don’t understand well, you should use Google or Baidu for in-depth study. The emphasis is on understanding.

The above is excerpted from the PHP Manual [2] - Overview of Common System Functions. For more related content, please pay attention to the PHP Chinese website (www.php.cn)!