PHP multiple serialization/deserialization methods

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. K7 Casino

1. Serialize and Unserialize functions

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

View Source print?

01

<?php

02

03	$a= array(‘a‘ => ‘Apple‘ ,‘b‘ => ‘banana‘ , ‘c‘=> ‘Coconut‘);

04

05

//序列化数组

06	$s= serialize($a);

07

echo$s;

08	//输出结果：a:3:{s:1:"a";s:5:"Apple";s:1:"b";s:6:"banana";s:1:"c";s:7:"Coconut";}

09

10	echo‘<br /><br />‘;

11

12

//反序列化

13	$o= unserialize($s);

14

15	print_r($o);

16	//输出结果 Array ( [a] => Apple [b] => banana [c] => Coconut )

17

18

?>

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.

View Source print?

1	$obj= array();

2

//序列化

3	$s= base64_encode(serialize($obj));

4

//反序列化

5	$original= unserialize(base64_decode($s));

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

View Source print?

01	//定义一个用来序列化对象的函数

02

03	functionmy_serialize( $obj)

04

{

05	returnbase64_encode(gzcompress(serialize($obj)));

06

}

07

08

//反序列化

09	functionmy_unserialize($txt)

10

{

11	returnunserialize(gzuncompress(base64_decode($txt)));

12

}

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.

View Source print?

01	$a= array(‘a‘ => ‘Apple‘ ,‘b‘ => ‘banana‘ , ‘c‘=> ‘Coconut‘);

02

03

//序列化数组

04	$s= json_encode($a);

05

echo$s;

06	//输出结果：{"a":"Apple","b":"banana","c":"Coconut"}

07

08	echo‘<br /><br />‘;

09

10

//反序列化

11	$o= json_decode($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.

View Source print?

01	$a= array(‘a‘ => ‘Apple‘ ,‘b‘ => ‘banana‘ , ‘c‘=> ‘Coconut‘);

02

03

//序列化数组

04	$s= var_export($a, true);

05

echo$s;

06	//输出结果： array ( ‘a‘ => ‘Apple‘, ‘b‘ => ‘banana‘, ‘c‘ => ‘Coconut‘, )

07

08	echo‘<br /><br />‘;

09

10

//反序列化

11	eval(‘$my_var=‘. $s. ‘;‘);

12

13	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.

View Source print?

01	$a= array(‘a‘ => ‘Apple‘ ,‘b‘ => ‘banana‘ , ‘c‘=> ‘Coconut‘);

02

03

//序列化数组

04	$s= wddx_serialize_value($a);

05

echo$s;

06

07	//输出结果（查看输出字符串的源码）：<wddxPacket version=‘1.0‘>

08

09	echo‘<br /><br />‘;

10

11

//反序列化

12	$o= wddx_deserialize($s);

13

14	print_r($o);

15	//输出结果：Array ( [a] => Apple [b] => banana 1 => Coconut )

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.

PHP multiple serialization/deserialization methods