Preferences – Code style issues Since the 2018.3 version we can enable the checkbox: Preferences/Settings > Editor > Inspections > Java > Code style issues > Local variable or parameter can be final Then perform the reformat code action. If the Code cleanup checkbox is enabled then IDEA will automatically add final where possible.
I can think of one scenario where it might be helpful to the compiler from an optimisation perspective. I’m not sure if it’s worth the effort to compiler implementers, but it’s theoretically possible at least. With virtual call dispatch on a derived, final type you can be sure that there is nothing else deriving from … Read more
Constant is the concept, the property of the variable. final is the java keyword to declare a constant variable. As other people pointed out, from a semantic/linguistic point of view the expression constant variable is an oxymoron and, as such, we could argue about its correctness. Quoting the specification, anyway, we can read A variable … Read more
Java does not allow you to create a class that extends an enum type. Therefore, enums themselves are always final, so using the final keyword is superfluous. Of course, in a sense, enums are not final because you can define an anonymous subclass for each field inside of the enum descriptor. But it wouldn’t make … Read more
“final” is a string literal and as such is a compile-time constant expression. The value of a static final variable initialized with a compile-time constant expression is directly hardcoded into the class which references it, and no reference is made to the originating class. Therefore the initialization of the originating class does not occur. As … Read more
It simply makes the local variable books immutable. That means it will always be a reference to that same Book object being created and built, and cannot be changed to refer to another object, or null. The Book object itself is still mutable as can be seen from the sequence of accessor calls. Only the … Read more
the reference to sharedData which is final is thread safe since it can never be changed. The contents of the Map is NOT thread safe because it needs to be either wrapped with preferably a Guava ImmutableMap implementation or java.util.Collections.unmodifiableMap() or use one of the Map implementations in the java.util.concurrent package. Only if you do … Read more
Because StatefulWidget inherits Widget, which is marked as @immutable, any subclass of StatefulWidget must also be immutable (i.e. all fields final). If you make a StatefulWidget subclass with non-final fields, it will result in this Dart analysis warning: info: This class inherits from a class marked as @immutable, and therefore should be immutable (all instance … Read more
You are hiding it, it’s a feature of “Scope”. Any time you are in a smaller scope, you can redefine all the variables you like and the outer scope variables will be “Shadowed” By the way, you can scope it again if you like: public class A implements I { public String KEY = “b”; … Read more
The “Java way” is inherently, intrinsically cluttery. I say it’s a good practice, but not one I follow. Tests generally ensure I’m doing what I intend, and it’s too cluttery for my aesthetics.