PHP is included in the file for variable sharing issues

Self - PHPIn the process encountered some problems, may be the problem will have common sense errors, please forgive me! Thank you!
Title, there are the following test cases
a.php

b.php

But in this case, there will be a warning in Zend Studio Undefined variable '$msg' , although not affecting the results of the operation, but for post-maintenance or other people's reading will have an impact, so I would like to ask what is the best way to solve this "obsessive-compulsive disorder" problem? Can you let Zend Studio not report this warning?

See the typecho source process to see the following statement, located in
/usr/themes/default/404.php

  
   
  
   need('header.php'); ?>                        
404 - 
            
 
                        
  
       
  
   need('footer.php'); ?>

How does that typecho make use $this need of access?
I have noticed that the typecho theme template is used $this to use the provided plug-in or function, and what is the principle?

Reply content:

The PHP process of self-study encountered some problems, there may be common sense errors, please forgive me! Thank you!
Title, there are the following test cases
a.php

b.php

But in this case, there will be a warning in Zend Studio Undefined variable '$msg' , although not affecting the results of the operation, but for post-maintenance or other people's reading will have an impact, so I would like to ask what is the best way to solve this "obsessive-compulsive disorder" problem? Can you let Zend Studio not report this warning?

See the typecho source process to see the following statement, located in
/usr/themes/default/404.php

  
   
  
   need('header.php'); ?>                        
404 - 
            
 
                        
  
       
  
   need('footer.php'); ?>

How does that typecho make use $this need of access?
I have noticed that the typecho theme template is used $this to use the provided plug-in or function, and what is the principle?

1. Do not use a bare global variable to wrap it into a class.

2. A template is a method include of an object that has this variable within its scope $this .

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