It doesn’t seem like there’s any point to it. According to the Java Language Specification 4.12.4: Declaring a variable final can serve as useful documentation that its value will not change and can help avoid programming errors. However, a final modifier on a method parameter is not mentioned in the rules for matching signatures of … Read more
When you declare a String (which is immutable) variable as final, and initialize it with a compile-time constant expression, it also becomes a compile-time constant expression, and its value is inlined by the compiler where it is used. So, in your second code example, after inlining the values, the string concatenation is translated by the … Read more
Java doesn’t support true closures, even though using an anonymous class like you are using here (new TimerTask() { … }) looks like a kind of closure. edit – See the comments below – the following is not a correct explanation, as KeeperOfTheSoul points out. This is why it doesn’t work: The variables lastPrice and … Read more
The logger reference is not a constant, but a final reference, and should NOT be in uppercase. A constant VALUE should be in uppercase. private static final Logger logger = Logger.getLogger(MyClass.class); private static final double MY_CONSTANT = 0.0;
In general, static means “associated with the type itself, rather than an instance of the type.” That means you can reference a static variable without having ever created an instances of the type, and any code referring to the variable is referring to the exact same data. Compare this with an instance variable: in that … Read more
… starting in Java SE 8, a local class can access local variables and parameters of the enclosing block that are final or effectively final. A variable or parameter whose value is never changed after it is initialized is effectively final. For example, suppose that the variable numberLength is not declared final, and you add … Read more
Usually not. For virtual methods, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn’t been overridden – until it loads a class which overrides the method, at which point it can undo (or partially undo) those optimizations. … Read more
There is a post on dart’s website and it explains it pretty well. Final: “final” means single-assignment: a final variable or field must have an initializer. Once assigned a value, a final variable’s value cannot be changed. final modifies variables. Const: “const” has a meaning that’s a bit more complex and subtle in Dart. const … Read more
Stop a Variable’s Reassignment While these answers are intellectually interesting, I’ve not read the short simple answer: Use the keyword final when you want the compiler to prevent a variable from being re-assigned to a different object. Whether the variable is a static variable, member variable, local variable, or argument/parameter variable, the effect is entirely … Read more
Assuming no SecurityManager is preventing you from doing this, you can use setAccessible to get around private and resetting the modifier to get rid of final, and actually modify a private static final field. Here’s an example: import java.lang.reflect.*; public class EverythingIsTrue { static void setFinalStatic(Field field, Object newValue) throws Exception { field.setAccessible(true); Field modifiersField … Read more