What is data serialization ?

Question

First of all, I could not able to get clear definition of it from WikiPedia or even from serialize function in the PHP manual. I need to know some cases we need the term seriali

Answer 1

Serialization is the process of turning data (e.g. variables) into a representation such as a string, that can easily be written and read back from for example a file or the database.

Use cases? There are many, but generally it revolves around the idea of taking a complex, nested array or object and turning it into a simple string that can be saved and read later to retrieve the same structure. For example, provided you have in php:

$blub = array();
$blub['a'] = 1;
$blub['a']['b'] = 4;
$blub['b'] = 27;
$blub['b']['b'] = 46;

Instead of going through every array member individually and writing it one could just:

$dataString = serialize($blub);

And the serialized array is ready to be written anywhere as a simple string, in such a way that retrieving this string again and doing unserialize() over it gets you the exact same array structure you had before. Yes, it's really that simple.