Preferred method to store PHP arrays (json_encode vs serialize)

Question

I need to store a multi-dimensional associative array of data in a flat file for caching purposes. I might occasionally come across the need to convert it to JSON for use in

Answer 1

First, I changed the script to do some more benchmarking (and also do 1000 runs instead of just 1):

I used this build of PHP 7:

PHP 7.0.14 (cli) (built: Jan 18 2017 19:13:23) ( NTS ) Copyright (c) 1997-2016 The PHP Group Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies with Zend OPcache v7.0.14, Copyright (c) 1999-2016, by Zend Technologies

And my results were:

serialize() (wins: 999) was roughly 10.98% faster than json_encode() unserialize() (wins: 987) was roughly 33.26% faster than json_decode() unserialize() (wins: 987) was roughly 48.35% faster than array json_decode()

So clearly, serialize/unserialize is the fastest method, while json_encode/decode is the most portable.

If you consider a scenario where you read/write serialized data 10x or more often than you need to send to or receive from a non-PHP system, you are STILL better off to use serialize/unserialize and have it json_encode or json_decode prior to serialization in terms of time.