Why are there no global variables in Java? (CoreJava)

Question :Why are there no global variables in Java? (CoreJava)
Answer :Global variables are considered bad form for a variety of reasons:
· Adding state variables breaks referential transparency (you no longer can
understand a statement or expression on its own: you need to understand
it in the context of the settings of the global variables).
· State variables lessen the cohesion of a program: you need to know more
to understand how something works. A major point of Object-Oriented
programming is to break up global state into more easily understood
collections of local state.
· When you add one variable, you limit the use of your program to one
instance. What you thought was global, someone else might think of as
local: they may want to run two copies of your program at once.
For these reasons, Java decided to ban global variables.