These functions are intended for work with WDDX.
In order to use WDDX, you will need to install the expat library (which comes with Apache 1.3.7 or higher).
After installing expat compile PHP with --enable-wddx.
The windows version of PHP has built in support for this extension. You do not need to load any additional extension in order to use these functions.
This extension has no configuration directives defined in php.ini.
This extension has no resource types defined.
This extension has no constants defined.
All the functions that serialize variables use the first element of an array to determine whether the array is to be serialized into an array or structure. If the first element has string key, then it is serialized into a structure, otherwise, into an array.
Note: If you want to serialize non-ASCII characters you have to convert your data to UTF-8 first (see utf8_encode() and iconv()).