Is it possible to create variables in java that will be available between all classes?

Question

Java

There are several variables (constants), and there are several classes. Variables are used in almost all classes. How to make them available to all classes without initialization?

Answer 1

static variable

Answer 2

If constant, then:
If variable, then:
public static

Answer 3

In general, it is bad practice to use global variables in OOP, but if you cannot do without them (and if they are constants), then fields with public static final modifiers are written in one class or interface, and then in all other classes these fields are accessed .