PHP implements a variety of serialization/deserialization methods

This article mainly introduces the PHP implementation of a variety of serialization/deserialization method, interested in the friend's reference, I hope to be helpful to everyone.

Absrtact: Serialization is the process of converting a variable into a string that can be saved or transmitted, and deserialization is the conversion of the string to the original variable at the appropriate time. Together, these two processes make it easy to store and transfer data, making the program more maintainable.

Serialization is the process of converting a variable into a string that can be saved or transmitted, and deserialization is the conversion of the string to the original variable at the appropriate time. Together, these two processes make it easy to store and transfer data, making the program more maintainable.

1. Serialize and Unserialize functions

These two are common functions for serializing and deserializing data in PHP.

<?php $a = array (' a ' = = ' Apple ', ' b ' = ' banana ', ' c ' = ' Coconut '); $s of serialized array = serialize ($a); Echo $s; Output: a:3:{s:1: "a"; S:5: "Apple"; s:1: "B"; S:6: "Banana"; s:1: "C"; s:7: "Coconut";} Echo ' <br/><br/> '; Deserialization $o = unserialize ($s); Print_r ($o); Output result Array ([a] = Apple [b] = Banana = Coconut)?>

Deserialization $o = unserialize ($s);p rint_r ($o);//output result Array ([a] + Apple [b] = Banana = Coconut)?>

Problems can occur when an array value contains characters such as double quotes, single quotes, or colons, which are deserialized. To overcome this problem, a clever trick is to use Base64_encode and Base64_decode.

$obj = Array ();//Serialization $s = Base64_encode (serialize ($obj));//Deserialization $original = Unserialize (Base64_decode ($s));

But base64 encoding will increase the length of the string. To overcome this problem, you can use it with gzcompress.

Defines a function my_serialize ($obj) {  return Base64_encode (gzcompress (Serialize ($obj)) that is used to serialize an object;} Deserialization function My_unserialize ($txt) {  return unserialize (gzuncompress (Base64_decode ($txt)));}

2. Json_encode and Json_decode

Serializing and deserializing using JSON format is a good choice:

Using Json_encode and Json_decode format output is much faster for serialize and unserialize formats.

The JSON format is readable.

The JSON format is smaller than the serialize return data result.

The JSON format is open and portable. It can also be used in other languages.

$a = Array (' a ' = = ' Apple ', ' b ' = ' banana ', ' c ' = ' Coconut ');//serialized Array $s = json_encode ($a); echo $s;//output: {"A": "A" Pple "," B ":" Banana "," C ":" Coconut "}echo ' <br/><br/> ';//deserialization $o = Json_decode ($s);

In the above example, the Json_encode output length is obviously shorter than the serialize output length in the previous example.

3. Var_export and Eval

The Var_export function outputs the variable as a string, and Eval executes the string as PHP code, deserializing the contents of the original variable.

$a = Array (' a ' = = ' Apple ', ' b ' = ' banana ', ' c ' = ' Coconut '); Serialized array $s = Var_export ($a, true); Echo $s; Output: Array (' a ' + = ' Apple ', ' b ' = ' banana ', ' c ' = ' Coconut ',) ' echo ' <br/><br/> '; Deserializes eval (' $my _var= '. $s. ';'); Print_r ($my _var);

4. Wddx_serialize_value and WDDX Deserialize

The Wddx_serialize_value function can serialize array variables and output them as XML strings.

$a = Array (' a ' = = ' Apple ', ' b ' = ' banana ', ' c ' = ' Coconut '); Serialized array $s = wddx_serialize_value ($a); Echo $s; Output (view source of output String): <wddxpacket version= ' 1.0 ' >

As you can see, there are more XML tag characters, resulting in a lot of space for serialization of this format.

Summary

All of the above functions perform normally when serializing array variables, but they are different when applied to objects. For example, the Json_encode serialization object fails. When deserializing an object, Unserialize and eval will have different effects.