Can PHP's singleton persist until the second request is sent?

What is the life cycle of the next PHP single case?
For example, I get a singleton in the first request and then assign the variable $ A to it. Does this make it possible to get this $ A variable when a second request is made?
About this knowledge, experienced pro, what good blog or book recommended to learn, thank you?

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What is the life cycle of the next PHP single case?
For example, I get a singleton in the first request and then assign the variable $ A to it. Does this make it possible to get this $ A variable when a second request is made?
About this knowledge, experienced pro, what good blog or book recommended to learn, thank you?

No, PHP is a single-process one-thread

The answer is no, because at the end of the script all the variables have been freed.

I think you need to know the life cycle of PHP.

      1. PHP是随着WEB服务器(apache)的启动而运行的；  2. PHP通过mod_php5.so()模块和服务器(apache)相连  3. PHP总共有三个模块：内核、Zend引擎、以及扩展层；  4. PHP内核用来处理请求、文件流、错误处理等相关操作；  5. Zend引擎（ZE）用以将源文件转换成机器语言，然后在虚拟机上运行它；  6. 扩展层是一组函数、类库和流，PHP使用它们来执行一些特定的操作。比如，我们需要MySQL扩展来连接MySQL数据库；  7. 当ZE执行程序时可能会需要连接若干扩展，这时ZE将控制权交给扩展，等处理完特定任务后再返还；  8. 最后，ZE将程序运行结果返回给PHP内核，它再将结果传送给SAPI层，最终输出到浏览器上。    

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