What kind of data is that?

Question

I'm going to use a plug-in in WordPress called RegistrationMagic. And I need to access the data saved for further use in front-end for a reason.

I was looking the tables in MySQL and found the data of the users like that:

a: 5: {
  i: 6;O: 8: "stdClass": 3: {
    s: 5: "label";s: 10: "First Name";s: 5: "value";s: 6: "Danilo";s: 4: "type";s: 5: "Fname";
  }i: 7;O: 8: "stdClass": 3: {
    s: 5: "label";s: 9: "Last Name";s: 5: "value";s: 5: "Teste";s: 4: "type";s: 5: "Lname";
  }i: 5;O: 8: "stdClass": 3: {
    s: 5: "label";s: 5: "Email";s: 5: "value";s: 26: "some@email.com";s: 4: "type";s: 5: "Email";
  }i: 8;O: 8: "stdClass": 3: {
    s: 5: "label";s: 7: "Website";s: 5: "value";s: 17: "http://teste.com/";s: 4: "type";s: 7: "Website";
  }i: 9;O: 8: "stdClass": 3: {
    s: 5: "label";s: 43: "Do you agree with our terms and conditions?";s: 5: "value";s: 2: "on";s: 4: "type";s: 5: "Terms";
  }
}

Someone can help me to understand what is that? It is JSON? Is possible work with it, like catch in a loop or something?

Sorry if this is a repost, because I always see this in my WordPress databases, but never figured out what is.

Answer 1

It's a serialized string. Here's a good description of what it is:

A PHP array or object or other complex data structure cannot be transported or stored or otherwise used outside of a running PHP script. If you want to persist such a complex data structure beyond a single run of a script, you need to serialize it. That just means to put the structure into a "lower common denominator" that can be handled by things other than PHP, like databases, text files, sockets. The standard PHP function serialize is just a format to express such a thing, it serializes a data structure into a string representation that's unique to PHP and can be reversed into a PHP object using unserialize. There are many other formats though, like JSON or XML.

So if you have a PHP array, object, etc., say

$array = array(
    'key value' => array(
        'more info' => array(1,2,3)
    ),
    'another key' => array(
        'and so on' => '<span>so on</span>'
    )
);  

With PHP you can use serialize() and unserialize() to turn it into a string. You can see yourself with a script like:

$storeArray = serialize($array);

echo "<pre>".print_r($storeArray,true)."</pre>";

$restore = unserialize($storeArray);

echo "<pre>".print_r($restore,true)."</pre>";

UPDATE: and as @TomJNowell reminded (thanks!):

WP auto-serialises and deserialises on the fly if you pass objects or arrays into APIs for saving

With Wordpress, for example with the Options API, passing your array into add_option() will save your array as a serialized string in the _options table. Retrieving the value with get_option() will auto-unseralizes it for you, and the value got will be the same as the original $array you passed added in:

add_option('my_array', $array);

$my_array = get_option('my_array');

echo "<pre>".print_r($my_array,true)."<pre>";