Simple PHP object serialization learning_PHP tutorial-PHP Tutorial-php.cn

PHP is still relatively commonly used, so I studied PHP object serialization and shared it with you here. I hope it will be useful to everyone. PHP object serialization is also a relatively common function, which can serialize an object into a string, which can be saved or transmitted. Let’s look at an example first:

<ol class="dp-xml">
<li class="alt"><span><span>classTestClass  </span></span></li>
<li class=""><span>{  </span></li>
<li class="alt"><span>var$a;  </span></li>
<li class=""><span>var$b;  </span></li>
<li class="alt"><span> </span></li>
<li class=""><span>functionTestClass()  </span></li>
<li class="alt"><span>{  </span></li>
<li class="">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">a</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">"Thisisa"</font></span><span>;  </span>
</li>
<li class="alt">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">b</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">"Thisisb"</font></span><span>;  </span>
</li>
<li class=""><span>}  </span></li>
<li class="alt"><span> </span></li>
<li class=""><span>functiongetA()  </span></li>
<li class="alt"><span>{  </span></li>
<li class="">
<span>return$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>a;  </span>
</li>
<li class="alt"><span>}  </span></li>
<li class=""><span> </span></li>
<li class="alt"><span>functiongetB()  </span></li>
<li class=""><span>{  </span></li>
<li class="alt">
<span>return$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>b;  </span>
</li>
<li class=""><span>}  </span></li>
<li class="alt"><span>}  </span></li>
<li class="">
<span>$</span><span class="attribute"><font color="#ff0000">obj</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">newTestClass</font></span><span>;  </span>
</li>
<li class="alt">
<span>$</span><span class="attribute"><font color="#ff0000">str</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">serialize</font></span><span>($obj);  </span>
</li>
<li class=""><span>echo$str;  </span></li>
</ol>

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Output result:

<ol class="dp-xml"><li class="alt"><span><span>O:9:"TestClass":2:{s:1:"a";s:9:"Thisisa";s:1:"b";s:9:"Thisisb";} </span></span></li></ol>

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Let’s analyze the string after serialization of an object.

<ol class="dp-xml">
<li class="alt"><span><span>O:9:"TestClass":2:  </span></span></li>
<li class=""><span>{  </span></li>
<li class="alt"><span>s:1:"a";s:9:"Thisisa";  </span></li>
<li class=""><span>s:1:"b";s:9:"Thisisb";  </span></li>
<li class="alt"><span>} </span></li>
</ol>

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First look at the content of the object itself: O:9:"TestClass":2:O means that this is an object type (object) , then 9 represents the name of the object, and 2 represents how many attributes the object has. Looking at the contents of the two attributes: s:1: "a"; s:9: "Thisisa"; in fact, it is similar to the contents of the array. The first item: s:1: "a"; describes the attribute name. The second item s:9:"Thisisa"; describes the attribute value. The following properties are similar. Let me first talk about an application of PHP object serialization. The following content is from the PHP manual, and the original text has not been changed. serialize() returns a string containing a byte stream representation of any value that can be stored in PHP. unserialize() can use this string to reconstruct the original variable value. Saving an object using serialization saves all variables in the object. The functions in the object are not saved, only the name of the class.

To be able to unserialize() an object, you need to define the class of the object. That is, if you serialize the object $a of class A in page1.php, you will get a string pointing to class A and containing the values of all variables in $a. If you want to deserialize it in page2.php and reconstruct the object $a of class A, the definition of class A must appear in page2.php. This can be achieved, for example, by placing the definition of class A in an include file and including this file in both page1.php and page2.php.

<ol class="dp-xml">
<li class="alt">
<span><strong><font color="#006699"><span class="tag"><?</SPAN><SPAN class=tag-name>php</SPAN></FONT></STRONG><SPAN> </SPAN></SPAN><LI class=""><SPAN>//classa.inc:  </SPAN><LI class=alt><SPAN>classA  </SPAN><LI class=""><SPAN>{  </SPAN><LI class=alt><SPAN>var$</SPAN><SPAN class=attribute><FONT color=#ff0000>one</FONT></SPAN><SPAN>=</SPAN><SPAN class=attribute-value><FONT color=#0000ff>1</FONT></SPAN><SPAN>;  </SPAN></SPAN><LI class=""><SPAN> </SPAN><LI class=alt><SPAN>functionshow_one()  </SPAN><LI class=""><SPAN>{  </SPAN><LI class=alt><SPAN>echo$this-</SPAN><SPAN class=tag><STRONG><FONT color=#006699>></span></font></strong></span><span>one;  </span>
</li>
<li class=""><span>}  </span></li>
<li class="alt"><span>}  </span></li>
<li class=""><span> </span></li>
<li class="alt"><span>//page1.php:  </span></li>
<li class=""><span>include("classa.inc");  </span></li>
<li class="alt"><span> </span></li>
<li class="">
<span>$</span><span class="attribute"><font color="#ff0000">a</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">newA</font></span><span>;  </span>
</li>
<li class="alt">
<span>$</span><span class="attribute"><font color="#ff0000">s</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">serialize</font></span><span>($a);  </span>
</li>
<li class=""><span>//将$s存放在某处使page2.php能够找到  </span></li>
<li class="alt">
<span>$</span><span class="attribute"><font color="#ff0000">fp</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">fopen</font></span><span>("store","w");  </span>
</li>
<li class=""><span>fputs($fp,$s);  </span></li>
<li class="alt"><span>fclose($fp);  </span></li>
<li class=""><span> </span></li>
<li class="alt"><span>//page2.php:  </span></li>
<li class=""><span>//为了正常解序列化需要这一行  </span></li>
<li class="alt"><span>include("classa.inc");  </span></li>
<li class=""><span> </span></li>
<li class="alt">
<span>$</span><span class="attribute"><font color="#ff0000">s</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">implode</font></span><span>("",@file("store"));  </span>
</li>
<li class="">
<span>$</span><span class="attribute"><font color="#ff0000">a</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">unserialize</font></span><span>($s);  </span>
</li>
<li class="alt"><span> </span></li>
<li class=""><span>//现在可以用$a对象的show_one()函数了  </span></li>
<li class="alt">
<span>$a-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>show_one();  </span>
</li>
<li class="">
<span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span>
</li>
</ol>

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