Question

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Why is require_once so bad to use?

I’ve read somewhere that the include_once and require_once statements in PHP were slower than their non-once counterparts. Is this a significant slowdown? Has there been any testing or studies of this, and has it changed in recent versions of PHP?

Answer 1

The speed increase is minimal and comes as a reference check is conducted to prevent code duplication. The ‘once’ appendage is a preventative measure against the same code being executed/included twice..this performing this check comes at a minor speed cost.

If there is ever an instance where you are using _once look into why it is the case, is you code really built in the most efficient way? It is often better to remove the need to rely on _once and produce better code (easier said than done!).

See:

http://forums.digitalpoint.com/showthread.php?t=1693837

http://www.phpbb.com/community/viewtopic.php?f=71&t=565933

http://www.sitepoint.com/forums/showthread.php?t=269085

http://www.quora.com/What-is-the-difference-between-functions-include-and-include_once-in-PHP