Java is a strongly typed language. What is meant by "strongly typed"?

Every variable must have an associated type before you can use it

Variables can be used without declaring their type

Every variable has a single type associated with it throughout its existence in the program, and the variable can only store values of that type

Variables are allowed to change type during their existence in the program as long as the value it currently stores is of the type it is currently declared to be

Variables are allowed to change types during their existence in the program but only if the change is to a narrower type