Why we need protection for data variable s ?

Question

who's gonna be broken the security of encapsulation? who is out side users ?

Answer 1

It's more about architecture.

Encapsulation hides variables or some implementation that may be changed so often in a class to prevent outsiders access it directly. They must access it via getter and setter methods.

It is important to take into consideration what parts of your program are doing what.

You should generally split up your code into logically consistent chunks.