java-just went from Java to PHP and encountered a problem referencing a class in another file.

Java Reference PHP Performance

Java/c# references are all in the first few lines of the file, and this Daniel wants me to write PHP with references to dynamic references written in a certain class of methods.
I am puzzled, performance, convenience ...
Daniel's usage is like this (using the thinkphp framework, we do not discuss the framework good or bad, only speak PHP):

 Class Test{    function onePerson(){            import "lib.Person";            $p=new Person();            $p->talk();    }    function killPerson(){            import "lib.Person";            $p=new Person();            $p->kill($t);    }    funtion conmunication(){    ....    }}

He said that the dynamic reference, when used in this method to reference the file can save resources, then the server pressure will be reduced.
But I think this is very troublesome to write, very often a sentence of the outcome of the matter with three sentences to write.

C#,java are not so written, code redundancy, bored to death. Excuse me, does this kind of photo performance be high? Or is it a worry?
The company is concerned with performance issues. Why don't you write that java,c#?

Please help me analyze the analysis, or help me to instill some theoretical knowledge.

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