In my view it makes the code extremely difficult to understand when someone other than the original author tries to read/modify.
The side effects of changing a global variables value is very difficult to glean from code.
It is as if some inputs to a function are getting passed to it implicitly, and it isn't obvious what value it has, who has set it, and what effect will be produced if you change its value.
The side effects of changing a global variables value is very difficult to glean from code.
It is as if some inputs to a function are getting passed to it implicitly, and it isn't obvious what value it has, who has set it, and what effect will be produced if you change its value.