How to debug in the class

How to debug in the class? For example, in a project, all the variables are called. in the controller, you can use the new function to test the variables, but in lib, variables are returned after several file classes are processed. the variables that directly call the lib file have no value. only the variables that are called by the controller have a value. How to debug in the class?
For example, in a project, all the variables are called. in the controller, you can use the new function to test the variables, but in lib, variables are returned after several file classes are processed. the variables that directly call the lib file have no value. only the variables that are called by the controller have a value. But there are a lot of variables (mainly arrays) for this purpose, and there is no comment. apart from dead-end reading, is there any more convenient method?

------ Solution --------------------
For specific debugging, we suggest you use either of the following methods:

1. track the call information of the class/method and format it to the response page. for details about the method, refer to the blog:

Http://blog.csdn.net/flex4/article/details/7050173

2. installing XDEBUG for debugging and tracking the methods one by one is also a good method. the XDEBUG installation method is as follows:

Http://www.xdebug.org/docs/install

Hope to help you. good luck :)