Overloading and Overriding

Why do we need Overloading and Overriding?

EJP, I'm just curious to know why you mention "*Overloading gives us the power to call a single method and pass it different parameters and the compiler at runtime decided which suitable method to call*" as a wrong answer.Because it is a wrong answer. The action occurs at compile time, not at runtime. The compiler isn't even present at runtime, by definition, so the statement is not just wrong but a contradiction in terms.
Is there any other reason for having overloading in java?The statement isn't a reason at all. It's just a definition, and an incorrect one, of what method overloading is. A definition is not a reason.
So why you're asking me for another reason when there hasn't been one provided at all in the entire thread, other than by me, is a complete, utter, and baffling mystery.
You seem to have the same problem ram has, of confusing 'what' with 'why', and of confusing definitions with reasons. One is bad enough, please let's not have two of you.

Similar Messages

What's the difference between "overloading" and "overriding" in Java

What's the difference between "overloading" and "overriding" in Java

hashdata wrote:
What is the real-time usage of these concepts...?Overriding is used when two classes react differently to the same method call. A good example is toString(). For Object it just returns the class name and the identityHashCode, for String it returns the String itself and for a List it (usually) returns a String representation of the content of the list.
Overloading is used when similar functionality is provided for different arguments. A good example is [Arrays.sort()|http://java.sun.com/javase/6/docs/api/java/util/Arrays.html#sort(byte%5B%5D)]: all the sort() methods do the same thing (they sort arrays), but one sorts byte-arrays, another one sorts int-arrays, yet another one sorts Object-arrays.
By the way, you almost certainly mean "real-world" usage. "real-time" (and thus "real-time usage) means something entirely unrelated to your question.

OO:overloading and overriding in tandem..Interesting one

Assume Dog IS-A Animal
class test {
public static void main(String[] args){
Animal a = new Dog();
foo(a);
void foo(Dog d){
d.printme();
void foo(Animal a){
a.printme();
}//end of class test
class Animal{
void printme(){
System.out.println("i am in animal");
}//end of class animal
class Dog{
void printme(){
System.out.println("i am in Dog");
}//end of class dog
Question:what will it print and explain how briefly u arrived at that result? (I assume u fix some obvious compile time errors(missing ; etc) as this is just a rough snippet)
NOTES-----------
1.Overloading has to do with reference type
2.Overriding has to do with the object to which it actually points

ok mlk..really sorry for being so naive.I sometimes don't clearly express my doubt. I jus got a doubt in my mind regarding overriding + overloading and i constructed a sample example as a concept(not actual code).
Here's the full fledged program..it compiles fine.And IS-A is perfectly satisfied in this case.
class Animal{
void printme(){
System.out.println("In Animal");
class Dog extends Animal{
void printme(){//overriding the Animal printme() method
System.out.println("In Dog");
public class TestDog {
void foo(Animal a){
a.printme();
void foo(Dog d){
d.printme();
public static void main(String[] args) {
Animal a = new Dog();
TestDog t = new TestDog();
t.foo(a); //method overloading
And it prints In Dog..as expected.Got it.Thanks.

BAPI Overloading and overriding

Hi Friends,
I just want to know Whether we can use BAPI Overloading and overiding concept is possible in BAPI?
Regards
Dinesh

Hello,
As far as I understand It is not possible but can you please explain little bit more about the requirement so we may think of some alternative.
Enjoy SAP!
Augustin.

Difrence bitween overloading and overriding

Plese give the definition & example for polymorphism

Polymorphism is of two types
1) static or design time polymorphism
2) dynamic or run time polymorphism
example for design time polymorphism is overloading (i.e) a method with same name shares diff signatures
For eg: arithmetic(int,int)
arithmetic(int,int,int)
example for run time polymorphism is overriding (i.e) a method with same name exists in both parent class and child class.
At run time it will be decided which method to call based on the object which calls it
Hope this clarifies yr query
Regards
Jansi

Difference between OVERLOADING and OVERRIDING??

Hi guys,
can you please exaplain me difference between Overloading & Overriding with example?
Thanks,
JaxNa

Here is the example of overriding :
/* PARENT CLASS */
package com.example.supreclass {
     public class parentClass {
          public function parentClass() {
          public function fromParent(myString:String):void {
               trace("Output :", myString);
/* DERIVED CLASS */
package com.example.supreclass {
     public class myExample extends parentClass {
          public function myExample() {
          /* Override the method */
          override public function fromParent(outputStr:String):void {
               super.fromParent(outputString);
               trace("Override example");
Overriding means redefining the inherited method (the parent method still can be invoked using 'super', as shown in example )
These links should give you some idea on these :
Overriding : http://www.kirupa.com/forum/showthread.php?p=1896981
Overloading means having many functions with same name but each differs by parameters it takes (either by data type or number of parameters passed) and return value.
Overloading : http://www.techper.net/2008/07/08/missing-method-overloading-in-as3/

About overloading and overriding

I hava a Java code like this:
class Homer {
float doh(float f) {
System.out.println("doh(float)");
return 1.0f;
char doh(char c) {
System.out.println("doh(string)");
return 'd';
class Bart extends Homer {
float doh(float f) {
System.out.println("doh(float)");
return 1.0f;
class Hide {
public static void main(String[] args) {
Bart b = new Bart();
b.doh('x');//compiler error in this line
b.doh(1);
b.doh(1.0f);
An error was ocurred:reference to doh is ambigous
Who can told me why?

andy.g
you are wrong!
you cannot undertand what is the different between
overlaoding and overiding!sorry for the wrong answer.
the point is the super-class's method with most specific signiture has the same priority as the sub-class's method that could match(not exactly the same, but can be promoted, like char to float) the signiture during method binding/finding. java always put the current class's method at the first place, but when a method in super-class is more specicif in signiture, the compiler can't determin which one to use.
actually, there is nothing related to overriding in this case, e.g.:
class A{
char method(char c){.....}
class B extends A{
//nothing's been overrided
float method(float f){......}
public static void main(String[] args){
B b = new B();
b.method('c'); //compiler error.
}so it is definetely a priority's problem, the super class's methods do not have the same prority as the sub-class's.

Overloading and bla extends bla

if class A extends class B and they have both got the same name on a method but different arguments does his make it overloading still or is it overriding?thanks in advance.

is it only overloading because they extend each other
or would it be anyway?It's just overloading because you have a class that has two methods with the same name.
and if the arguments where the
same would it still be overloading?No, that would be overriding, and only if that method is inherited.
sorry im asking so
much but i'm having trouble understanding the whole
overloading and overriding situations when its
extending a class is involved,does it make a
differance?thanksYes, it does, to overriding. X defines an implementation that you want to change. If Y doesn't inherit it, there is nochting to change. You'd just be implementing yet another method.

Can we use overload and overwrite concept in OO-abap

hi
can we use overload and overwrite concept in OO-abap

Hi
CLASS zl_lcl_vehicle DEFINITION.
PUBLIC SECTION.
Signature of method
METHODS: set_make
IMPORTING value(im_make) TYPE string " Pass by value
im_model TYPE string," Pass by reference
ENDCLASS. "zl_lcl_vehicle DEFINITION
CLASS zl_lcl_vehicle IMPLEMENTATION.
Implementation of method.
METHOD set_make.
IF im_make IS NOT INITIAL
AND im_model IS NOT INITIAL.
gv_make = im_make.
gv_model = im_model.
ENDIF.
ENDMETHOD. "set_make
ENDCLASS. "zl_lcl_vehicle
Overloading means changing signature as well as implementation of a method.
Overriding is changing only implementation of method with signature unchanged.
From ABAP perspective, only the CONSTRUCTOR method can be overloaded in a subclass i.e both the signature and implementation can be adapted in subclass.
Any other method can't be overloaded. It can only be redefined/overridden i.e implementation changed with signature unchanged.
In ABAP there is something called a redefinition.
When you inherit a class from a super class, you can redifne a method. You cannot chnage the signature( Interface) of the method. It will remain the same as that of the super class.You must redefine a method in the same visibility section in which it appears in the superclass.
Eg.
CLASS C_SUPER_CLASS DEFINITION .
PUBLIC SECTION.
METHODS: DRIVE ,
STOP.
PROTECTED SECTION.
DATA SPEED TYPE I.
ENDCLASS.
CLASS C_SUPER_CLASS IMPLEMENTATION.
METHOD DRIVE.
SPEED = 0.
WRITE: / 'Bike speed =', SPEED.
ENDMETHOD.
ENDCLASS.
CLASS C_SUB_CLASS DEFINITION INHERITING FROM C_SUPER_CLASS.
PUBLIC SECTION.
METHODS DRIVE REDEFINITION.
ENDCLASS
CLASS C_SUB_CLASS IMPLEMENTATION.
METHOD DRIVE.
SPEED = SPEED + 10.
WRITE: / 'Bicycle speed =', SPEED.
ENDMETHOD.
ENDCLASS.
Regards
Vasu

Extending classes and overriding methods

If I have a class which extends another, and overrides some methods, if I from a third class casts the extending class as the super class and calls one of the methods which gets overrided, is it the overrided method or the method of the superclass which get executed?
Stig.

Explicit cast can't enable the object to invoke super-class's method. Because dynamic binding is decided by the instance. The cast can just prevent you from using methods only defined in sub-class, but it does not let the object to use super-class's method, if the method's been overrided. Otherwise, the polymophism, which is one of the most beautiful feature of Object-Oriented thing, can't be achieved. As far as I know, the only way to use super-class's method is the super keyword in the sub-class, and seems no way for an object to do the same thing (I may wrong, since I haven't read the language spec).
here's a small test:
public class Test {
public static void main(String[] args){
A a = new B();
a.method();
((A)a).method();
class A{
public void method(){
System.out.println("A's method");
class B extends A{
public void method(){
System.out.println("B's method");
The output is:
B's method
B's method

Server Overloaded and Warning Status

I have a WebLogic cluster, includes 3 Managed Server running on 2 separate machines (Each has 16Gb Ram and 8 CPU - Sun Sparc). Each start with parameters
Starting WLS with line:
/usr/jdk/instances/jdk1.6.0/bin/java -server -Xms1024m -Xmx2048m -XX:MaxPermSize=128m
Some time ManagedServers have status "OverLoaded" and "Warning". When that happened , I stop and start server and server status return to OK.
Checking the status with "prstat" command, I saw that java process used just from 1Gb Ram to 2Gb Ram and CPU is under 3%, very little CPU used
What I have to do to make server return to OK status without restart?
And how to make server running with OK status everytime?
And How many Managed Server can I create on each machine with that hardware?
Thank you!

What I have to do to make server return to OK status without restart?Maybe stop some or all applications can be usefull.
And how to make server running with OK status everytime?You must tuning the enviroment, maybe should adjust JVM parameters passed to weblogic server, check thread pools, etc. For Sun HotSpot JVM, you can use -XX:+AggressiveHeap option for throughput applications, give it a try.
See [WebLogic Server Performance And Tuning|http://download.oracle.com/docs/cd/E13222_01/wls/docs92/perform/index.html]
And How many Managed Server can I create on each machine with that hardware?This decision depends on applications you want run, weblogic resources required, how many clients will be attended, and so on. If your weblogic server using 8GB achieves the goal, then you can setup another instance using the remaining available, and so on.
I hope this helps.

Compensation Default and override - Component Id error

Hi,
I am working on a fast formula of 'Compensation default and override type' .
The logic within requires 'component id'. There is an input variable CMP_IV_COMPONENT_ID for this formula type .
I am attaching the fast formula to a component specific column in the worksheet for a particular plan.
I back the plan and start it.
The formula is not getting executed at all.
I also tried attaching this formula to a normal column (which is not specific to a component) .. But in this case the component id was not recognized and the start Batch process errored out.
Please let me know how to attach this type of formula to a plan and run it .
Edited by: 998873 on May 13, 2013 11:34 PM

Please note ASG_HR_ASG_ID and PAYROLL_ASSIGNMENT_ID are not same in Fusion. That's why it' not returning any value as element entries are created for payroll assignment id. Since you are able to get value for ASG_HR_ASG_ID, it must be setting value for PAYROLL_ASSIGNMENT_ID as well. Please check value for PAYROLL_ASSIGNMENT_ID and EFFECTIVE_DATE context using following code:-
L_EFFECTIVE_DATE_TEMP='0001/01/01 00:00:00' (Date)
L_PAY_ASG_ID = GET_CONTEXT( PAYROLL_ASSIGNMENT_ID, -1)
L_EFFECTIVE_DATE=GET_CONTEXT(EFFECTIVE_DATE,L_EFFECTIVE_DATE_TEMP)
If it's returning value, it means payroll assignment id and effective date contexts are already set and you don't need to set them explicitly. You can directly get value for STOCK_OPTIONS_NUMBER_OF_SHARES_ASG_ENTRY_VALUE.
Hope this help!

Hiding and overriding clarifications

I am trying to understand the Java language specification document,
one of the worst technical docs I've seen in 35+ years in the business.
Right now I'm trying to clarify the implications and meanings of these
two terms (hiding and overriding) in a very simple environment. Maybe
someone here can make it clear.
Context is just basic classes with fields, initializers, constructors, and
methods; no interfaces, no nested classes. Keep it clear and simple.
When I create a subclass, I understand that fields and methods are
inherited. I also understand how hiding of fields works, and how to
access a hidden field from an external class.
But methods. Sheesh! At first I thought maybe fields are hidden and
methods are overridden. But, no, because there's 8.4.10.5 titled
"Example: Invocation of Hidden Class Methods". So a method can
be hidden, and a hidden method can be accessed.
So, here are my questions:
* What is the difference between overriding a method and hiding a method?
* How can you tell / demonstrate a method is hidden or overridden?
* If a method is overridden, is it always inaccessible from an external class?
* Are there pitfalls to avoid with hiding / overriding methods?
* Are there features to exploit with hiding / overriding methods?
* Do instance methods have different behaviors / facilities than
class methods, as far as hiding and overriding?
Thanks.

* What is the difference between overriding a
method and hiding a method?Overriding a method means the subclass chooses not to use the parent class's implementation. Hiding a method I assume means you declare a method private so that a subclass cannot use it.
* How can you tell / demonstrate a method is hidden
or overridden?The modifier private will be applied to methods that are hidden. Overridden methods will have the same signature as the parent and are thus easy to spot as well.
* If a method is overridden, is it always
inaccessible from an external class?You're confused. Hidden/private methods affect visibility. Overriding a method doesn't change it's visibility so external classes may or may not be able to access it. It all depends on the access modifiers you've applied
* Are there pitfalls to avoid with hiding /
overriding methods?You'd have to provide a specific scenario for this question. This is too open-ended.
* Are there features to exploit with hiding /
overriding methods????
* Do instance methods have different behaviors /
facilities than
class methods, as far as hiding and overriding?What you're talking about is static vs. instance methods. Google it, I'm done for now.

About hiding and overriding

Hi,can u tell what is the difference between hiding and overriding.
Is hiding only applied to class method(static) and overriding only applied to instance method?
It is a must to use "super" keyword to use a overridden method.Is that right?
And Look at the code below:
Can u tell why s.greeting is refer to static method of super while s.name() refer to method of sub?
What is type and what is class then? Any difference?
I have read the doc of Java Spec and still do not feel clear about it.Thank you for attention.
class Super {
static String greeting() { return "Goodnight"; }
String name() { return "Richard"; }
class Sub extends Super {
static String greeting() { return "Hello"; }
String name() { return "Dick"; }
class Test {
public static void main(String[] args) {
Super s = new Sub();
System.out.println(s.greeting() + ", " + s.name());

It's not necessarily a must to use the "super" keyword in an overridden method. If your class extends some class called "TopClass", and "TopClass" has a constructor, then you must use the super keyword as the first statement in the constructor of your class.
When you extend a class, your class becomes a type of that class. If you want to override methods, the only requirement (that I know of) is that only the method's body can differ from that of it's super class.
i.e.
Here's a method from some super class:
public boolean mySuperMethod(String s) {
System.out.println("Hi");
return true;
Here's the overridden method from an extended class:
public boolean mySuperMethod(String s) {
boolean b = false;
return b;
As you can see, you can do whatever you want inside the method, but everything else has to stay the same (as far as I know).
Here's another example that I did a while back. It's a checkbox that can't be tabbed to and can't accept user actions. I used it simply as an indicator for something.
import java.awt.*;
public class NonTraversableCB extends Checkbox
     public NonTraversableCB()
          super();
     public NonTraversableCB(String label)
          super(label);
     public boolean isFocusTraversable() {
          return false;
     public void processEvent() {
          return;

List what monitors and overrides a specific server have

Hi,
I really need help with this!
I am migrating servers from a very messy scom 2007r2 enviroment.
I have installed a new scom 2012r2 enviroment and are trying to import server by server. I need to have all monitors and overrides listed soo I know what have been monitored before soo I can set it up in the new enviroment also.
I can not import whole management packs because then I have all the mess in the new enviroment aswell.
Soo I need to get a list like this:
Server1
Exchange 2007 monitor
Custom monitor process lanman.exe
Custom monitor service Print spoolsv
Override no alerts on print spoolsv
Is this possible to do? Please please help me!

For SCOM 2007 R2, Microsoft had develop a tool called Effective Configuration Viewer that can displays the set of rules and monitors that are running on a computer and can export the result into xml file. You can download the file from
http://www.microsoft.com/en-us/download/details.aspx?id=6742
Roger
That was a really nice tool! Never heard of before, thank you very much!

Overloading and Overriding

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