Some other tips for PHP developers.

Inspired by this .

I decided to recall some features of PHP related to performance.

I will note that I included in my small list only what is usually surprising to junior developers with whom I had to work.
I think everyone knows about banal things like “single quotes instead of double quotes”, so I will try to surprise anyone.
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The results and conclusions are made on the basis of several versions of PHP, which revolve on servers I know, namely 5.2.6 from Debian Lenny, 5.3.2 from Ubuntu, and 5.2.14 from dotdeb. Perhaps on other platforms, there are differences.

• file_get_contents
  , file_get_contents, (memory mapping), , .
  :
  simplexml_load_string( file_get_contents ('file.xml') )
  , :
  simplexml_load_file('file.xml')
  , simplexml_load_file , fopen/fread, .
  
  NB: DOM->loadFile, .
  
  \n ( CSV, TSV, ), file()
  explode(PHP_EOL, file_get_contents('file.xml'));
  c PHP_EOL LoneCat
  , xml.
  , file() — .
  
• count() sizeof()
  UPD: sizeof() count(), , merkushin .
  
• Notices, etc.
  , , .
  junior developer, , , notice PHP , 30- .
  
• foreach
  foreach, , PHP, .
  , . , :
  while (list($key, $value) = each($item))
  , .
  $key, foreach 30-40%.
  
• JSON vs XML
  , json- , 20-30% . JSON , .
  , json_decode ( , ), .
  
• mb_ereg vs preg_match
  POSIX — , , .
  Oniguruma, mb_ereg, mb-, , , preg_match.
  
• IGBinary .
  , .
  
• file_exists include
  file_exists() include, , include(), , , , .
  
• include
  , include_once, ( ).
  
• Static vars
  , , 5 — 10 .
  
• ,
  , .
  (, «100 » «0.1 »), .
  , , , : , , , ...
  , ( testing-) , - (: «Achtung! 30% MySQL»).
  

.
, .

, , , .

, , http://phpbench.com/ ( )

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