It takes a different thought pattern. A static method is not bound to an object and there is hence no notion of this nor super in a static method.
If you declare the same method in a subclass, you hide the superclass method instead of overriding it.
Is 'Koi no Summer Vacation' better translated as 'Love of Summer Vacation' instead of 'Summer Vacation of Love'.
Another was the decision that the target audience for Java was C++ developers.
Overriding in Java simply means that the particular method would be called based on the run time type of the object and not on the compile time type of it (which is the case with overriden static methods). The static call is resolved at compile-time, whereas a non-static method call is resolved at run-time. In Java (and many OOP languages, but I cannot speak for all; and some do not have static at all) all methods have a fixed signature - the parameters and types. That's an language's API keyword.
Otherwise great confusion would ensue.
Since you are working in Java, you will need to adjust to that way of doing things. No, we cannot override static methods because method overriding is based on dynamic binding at runtime and the static methods are bonded using static binding at compile time.
We can have two or more static methods with the same name, but differences in input parameters. You get only a "description" of the class -- not the class itself. A Static method, variable, block or nested class belongs to the entire class rather than an object.
Therefore, while designing the java programming language. See the "Class" class. I think Delphi was the first language implementing OOP used in commercial application development and wide-known. Well, probably to improve performance at the time based on the technology and understanding that was available.
For instance, Scala's equivalent of "static classes" (which are called, There is a compile-time type hierarchy and a run-time type hierarchy. However, all this would do is to re-implement regular class methods, adding redundancy to the language without really adding any benefit. This is just something you will have to accept when working with Java (or C#). How can I use parentheses when there are math parentheses inside? Secondly, to hide the behaviour of a class from outside world.
It compiles successfully without any errors but at the runtime, it says that the main method is not public. It could conceptually be possible if you could call static methods from class objects (like in languages like Smalltalk) but it's not the case in Java. At the moment, Java has this "quirk" in the language whereby obj.staticMethod() calls are replaced by ObjectClass.staticMethod() calls (normally with a warning). As static methods are class methods they are not instance methods so they have nothing to do with the fact which reference is pointing to which Object or instance, because due to the nature of static method it belongs to a specific class. You can then override this singleton with a new class and the methods in the previous class object will call those defined in the new class (correct?). How do I unwrap this texture for this box mesh?
If a method cannot be inherited, then it cannot be overridden. This would easily be doable (if we changed Java :-O), and is not at all unreasonable, however, it has some interesting considerations. Many other languages support overriding static methods, as we see in previous comments.
Did you not read any of the other answer already covering this and making it clear that these are not reasons enough to discount overriding statics at the conceptual level. to override), CORE JAVA - Top 120 most interesting and important interview questions and answers in core java, Serialization and Deserialization Java Quiz - MCQ, Differences between Instance initialization block and Static initialization block in java - Features in detail with programs, Solve [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project Maven: Compilation failure: Compilation failure: diamond operator is not supported in -source 1.5 (use -source 7 or higher to enable diamond operator), Core Java Tutorial in detail with diagram and programs - BEST EXPLANATION EVER.
of the object and not on the compile-time type of it (which is the case with overridden static methods). What is a serialVersionUID and why should I use it?
I feel Jay has also come to Java from Delphi like me.
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Overriding in Java simply means that the particular method would be called based on the runtime type static class members do not belong to a particular instance.
Argument of \pgfmath@dimen@@ has an extra }, Possible deltaV savings by usage of Lagrange points in intra-solar transit. I think the example I give is a very natural thing to want to do. Now, here's where the static keyword starts to make sense: the word "static" is an antonym for "dynamic". Personally I think this is a flaw in the design of Java.
You still have class but it is hidden in the VM (near the class loader), user have almost no access to it. That seems like a very roundabout way to get there.
What good will it do to override static methods.
Overriding depends on having an instance of a class. I personally prefer to use static methods to perform some actions without creating any instance of a class. I think that the rules would make things quite complicated.
Notice that although static methods are inherited (from parent) they are not overridden (by child).
Overriding in Java means that the method would be called on the run time based on type of the object and not on the compile time type of it . This is quibbling for quibbling's sake. No, the Methods that are declared as final cannot be Overridden or hidden. (Admittedly, this example is poor coding style in that in real life you would likely want the bonus multiplier to be in a database somewhere rather than hard-coded.
Likewise, all compilers will prevent subclasses from overriding final methods. This is a question our experts keep getting from time to time. I've run into this situation a fair number of times over the years. This is routinely touted as a positive feature for ordinary virtual functions, not a problem. (Besides the obvious "making it work right was too hard"), @VicKirk: If you mean that this is "bad design" because it doesn't fit how Java handles statics, my reply is, "Well, duh, of course."
The compiler decides which method gets called. Then when wherever you Assign a Dog object to an Animal Reference and call eat() according to Java Dog's eat() should have been called but in static Overriding Animals' eat() will Be Called. Go troll somewhere else. A final method declared in the Parent class cannot be overridden by a child class. Very cool, it's the first time I have heard about the Haxe programming language :). We can declare static methods with the same signature in the subclass, but it is not considered overriding as there won't be any run-time polymorphism.
But the difference is subtle. This could be a surprise if you expected otherwise.
This is because, here we are not overriding a method but we are just re-declaring it. Why they did this?
https://stackoverflow.com/a/2223803/1517187, http://faisalbhagat.blogspot.com/2014/09/method-overriding-and-method-hiding.html, Code completion isnt magic; it just feels that way (Ep. "I already told you the price!" Why should something like a Date instance NOT call its own static methods passing instance data to the function through the calling interface? @WJS I have never heard about Simula or other languages that supported OOP. This is much better implemented in Java as a static method on the class itself; Your are right, it is a classic solution.
So even if you have written, but only "correct" in Java. I think Jay has a point - it surprised me too when I discovered that statics could not be overridden.
It is perfectly "clean to desire the overriding of static methods and indeed it IS possible in many other languages.
This is not true in a lot of instances where at runtime the static method is in fact called from an instance of the containing class and thus it's perfectly feasible to determine which instances of the function to invoke. Yes, a static class can have static constructor, and the use of this constructor is initialization of static member. Actually, static methods in Delphi are called "class methods", while Delphi had the different concept of "Delphi static methods" which were methods with early binding.
it makes as much if not more sense than creating a class factory, except static. The point of polymorphism is that you can subclass a class and the objects implementing those subclasses will have different behaviors for the same methods defined in the superclass (and overridden in the subclasses).
SuperClass: inside staticMethod
Namely, SpecialEmployee's get a 2% bonus just like regular employees. You can overload static method, that's ok. Please enable JavaScript!Bitte aktiviere JavaScript!S'il vous plat activer JavaScript!Por favor,activa el JavaScript!antiblock.org.
There is no concrete reason to disallow the overriding of static methods other than "that's how it is".
But static methods are class methods access to them is always resolved during compile time only using the compile time type information. Therefore, any other code that calls this must must not attempt to put a reference to an object on the stack.
So can you override an overloaded function?
It makes perfect sense to ask why a static method call doesn't avail itself of the run-time type hierarchy in those circumstances where there is one. Our team has collected thousands of questions that people keep asking in forums, blogs and in Google questions. It seems quite plausible to me that you might want to make getBonusMultiplier static.
(I fear this is turning into one of those conversations where we're just not communicating.
by using, is always going to invoke static method() of, Assign any sub type object to reference of superclass [. ]
So the term "overriding" static methods itself doesn't make any meaning.
Of course it means that method() would mean this.method() if method was a non-static method, and ThisClass.method() if method were a static method.
464), How APIs can take the pain out of legacy system headaches (Ep. Class can have private constructor. This also saves the unnecessary wastage of memory which would have been used by the object declared only for calling the main() method by the JVM.
"Okay, I know the price, but I was asking about the color."
What would be the point of searching for such example instances? I agree that this is the bad design of Java.
this) so then it is possible to reference anything within the heap that belong to that instance of the object. So it is counter-intuitive to override static method which is not even associated with objects but the class itself in the first place. The main consideration is that we need to decide which static method calls should do this.
One was a concern with performance: there had been a lot of criticism of Smalltalk about it being too slow (garbage collection and polymorphic calls being part of that) and Java's creators were determined to avoid that.
So if you called a method in the context of the original class it still would only execute the original statics, but calling a method in the derived class, would call methods either from the parent or sub-class. And yes, yes, I can think of any number of ways to rewrite the above code to make it work. After all, the compiler knows what class each object is an instance of.
Classes do exist as objects in Java.
Well the answer is NO if you think from the perspective of how an overriden method should behave in Java. @Yishai: RE "Runtime instance dictate which static method is called": Exactly. But is there a good reason why it SHOULD behave this way?
You can reflect over the classes, but it stops there.
Richard, let's assume for a minute that when I responded to this question 4 years ago most of these answers had not been posted, so don't be an ass! Static methods are treated as global by the JVM, there are not bound to an object instance at all.
Because of this difference between the two; virtual methods always have a reference to the context object (i.e. Even many modern languages like Ruby have class-methods and allow overriding them.
I see that in Ruby classes are really a special kind of object and one can create (even dynamically) new methods. Taking the Employee example, if we call RegularEmployee.getBonusMultiplier() - which method is supposed to be executed? overriding is reserved for instance members to support polymorphic behaviour. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA.
It will allow overrides and inheritance.
When you say overriding static methods, the words you are trying to use are contradictory.
If we did it would make method bodies harder to read: static calls in a parent class could potentially be dynamically "re-routed".
You can use reflection to get the class of an object at run-time, but the object that you get does not parallel the class hierarchy. Method overriding is made possible by dynamic dispatching, meaning that the declared type of an object doesn't determine its behavior, but rather its runtime type: Even though both lassie and kermit are declared as objects of type Animal, their behavior (method .speak()) varies because dynamic dispatching will only bind the method call .speak() to an implementation at run time - not at compile time. In the future, there will be other new ideas. A static method is associated with a class while an instance method is associated with a particular object. The short answer is: it is entirely possible, but Java doesn't do it.
What's wrong with the concept?". So it was very convenient and intuitive and I would expect this in Java. No, we cannot override private or static methods in Java. My bad. If you wish that Java would change the definition so that a object context is passed in for every method, static or virtual, then you would in essence have only virtual methods.
And - yes, we could in Delphi override static methods. Yes, yes, I understand that non-static methods are attached to an instance while static methods are attached to a class, etc etc. Generally nobody does that.
BTW, in a very real sense static functions are called with an instance quite routinely: When you call the static function from within a virtual function. Indeed Java does allow static members to be accessed via instances: see.
"Separate hierarchy": I'd say, Make it part of the same hierarchy. Java allows re-declaration of a method (static/non-static). According to Polymorphism Principle of Java, the Output Should be Dog Eating. EDIT: One other comment.
Hence the answer is 'No'.
EDIT : It appears that through an unfortunate oversight in language design, you can call static methods through an instance.
Notice the second line of the output. I suggest they do the same as today, and use the local class context to decide what to do. Dynamic polymorphic behavior comes when a programmer uses an object and accessing an instance method.
I like and double Jay's comment (https://stackoverflow.com/a/2223803/1517187).
instead, static members belong to the class and as a result overriding is not supported because subclasses only inherit protected and public instance members and not static members.
A Method in Java is used to expose the behaviour of an Object / Class. Also, I'd try to avoid using so much Meth while programming ; Why doesn't Java allow overriding of static methods? etc.). If water is nearly as incompressible as ground, why don't divers get injured when they plunge into it? It just wasn't designed to do it.
In general it doesn't make sense to allow 'overriding' of static methods as there would be no good way to determine which one to call at runtime.
See Java oracle docs and search for What You Can Do in a Subclass for details about hiding of static methods in sub class. It is obvious that many people had experience with that language since it was in the past the only language to write commercial GUI products.
This answer, while correct, is more akin to "how it is" rather than how it should be or more accurately how it could be in order to meet the expectations of the OP and, hence here, myself and others. Are there any legitimate reasons to hide static methods? Your comment does not add anything of value to this thread.
Furthermore, did you not read that we are only discussing overriding with respect to Java.
Static methods return constant results while running (for a specific class) => static. Yes. There were two considerations driving Java's design that impacted this.
What if we are creating a new category of employee and don't have any employees assigned to it yet? (from OCA practice test). Here is some code which illustrates the current state of affairs in Java: If you run this (I did it on a Mac, from Eclipse, using Java 1.6) you get: Here, the only cases which might be a surprise (and which the question is about) appear to be the first case: "The run-time type is not used to determine which static methods are called, even when called with an object instance (obj.staticMethod()).
I was thinking the same as you, but then learned about Ruby/Smalltalk 'class' methods and so there are other true OOP languages that do this.
Who cares what's possible in other languages.
When you say overriding static methods, static methods we will access by using the class name, which will be linked at compile time, so there is no concept of linking methods at runtime with static methods.
Accessing them using object references is just an extra liberty given by the designers of Java and we should certainly not think of stopping that practice only when they restrict it Here, as the method is static (i.e, static method is used to represent the behaviour of a class only.) and just an extra liberty given by the java designers.
Short satire about a comically upscaled spaceship.
Which was charles darwins contribution to the study of biology.
SuperClass: inside staticMethod There is nothing conceptually wrong with being able to call a static method through an instance. Private methods in Java are not visible to any other class which limits their scope to the class in which they are declared. more details and example Interesting and I can see some value in that.
By overriding we can create a polymorphic nature depending on the object type.
That means, if you try to override, Java doesn't stop you doing that; but you certainly don't get the same effect as you get for non-static methods.
why static method cannot be overridden in java
