kabir soni

 Profile Answers by kabir soni Questions by kabir soni

• Feb 6th, 2009

By manually calling the gc() method of Runtime class

sampra

 Profile Answers by sampra Questions by sampra

• Feb 14th, 2008

we can use System.gc() and System.runFinilize() to request garbage collection

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javabuddy

 Profile Answers by javabuddy Questions by javabuddy

• Jan 10th, 2011

Between two Enumeration is older and its there from jdk 1.0 while iterator was introduced later. The functionality of Enumeration interface is duplicated by the Iterator interface. Iterator has a rem...

chandaka

 Profile Answers by chandaka Questions by chandaka

• Sep 22nd, 2009

The functionality of this interface is duplicated by the Iterator interface. In addition, Iterator adds an optional remove operation, and has shorter method names. New implementations should consider using Iterator in preference to Enumeration.

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Rohit Manjunath Balekundri

• Jun 8th, 2017

Java: is a object oriented language for building platform independent application with OOPS concepts with set of API provided by Oracle. Originally it was owned Sun micro systems.

Core Java: is a core/basic API to develop desktop applications.

Ankur

• May 31st, 2017

Core Java is part of Java. Java has Core Java (J2SE), J2EE, J2ME.

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sat.beit

 Profile Answers by sat.beit Questions by sat.beit

• Jun 6th, 2008

Main method define in class from which excution of the application will get start.Which u can called main class of the file and file name will be the same as mainclass.

dvs198528

 Profile Answers by dvs198528 Questions by dvs198528

• Jun 6th, 2008

Public static void main(String ar[]) is in the class whose name is same as the name of the program name.Reason : To start the execution of the program initiating from main().

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akansha

• Feb 28th, 2018

As you say abstract class has no complete body that is why we cannot create object but if we completed this body after that we also cannot create object why?

Rowan Siwakoti (NepWeb)

• Jun 10th, 2016

We can create object of an abstract class indirectly by using anonymous inner class. Thank you :)

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mani.sivapuram

 Profile Answers by mani.sivapuram Questions by mani.sivapuram

• Apr 14th, 2011

String is a immutable.What is immutable the state of an object is not changed if we initilize once.i.e for example String s1="Geek"          ...

sankarsansinha

 Profile Answers by sankarsansinha Questions by sankarsansinha

• Feb 5th, 2009

String objects are constants and immutable where as StringBuffer objects are not.StringBuffer Class supports growable and modifiable string where as String class supports constant strings. Strings onc...

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harry

• Nov 2nd, 2017

Very first I would like to tell you that String not a data type its Final class and that present in java.lang package and its a drive class Question is that Why it is derived class

vivek

• Aug 26th, 2017

Strings are data types that can hold everything and by everything I mean primitives types as well as user defined types. Moreover the meaning of word string is something which connected for e.g a thre...

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sampra

 Profile Answers by sampra Questions by sampra

• Feb 22nd, 2008

One majar diff also is string obj are immutable where as string buffer objects are mutable  

paddu

• Oct 12th, 2007

Strings are immutable that means we cann't change the content or data. Where in the case of StringBuffer we can change the data or content that are presented in that.

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In how many ways we can create an object? Explain with example.

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vishrutha  

 Profile Answers by vishrutha Questions by vishrutha

• Member Since Feb-2009 | Feb 13th, 2009

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1. Using new keyword
This is the most common way to create an object in java. I read somewhere that almost 99% of objects are created in this way.

MyObject object = new MyObject();

2. Using Class.forName()
If we know the name of the class & if it has a public default constructor we can create an object in this way.

MyObject object = (MyObject) Class.forName("subin.rnd.MyObject").newInstance();

3. Using clone()
The clone() can be used to create a copy of an existing object.

MyObject anotherObject = new MyObject();
MyObject object = anotherObject.clone();

4. Using object deserialization
Object deserialization is nothing but creating an object from its serialized form.

ObjectInputStream inStream = new ObjectInputStream(anInputStream );
MyObject object = (MyObject) inStream.readObject();

5. Using class loader
one more is through creation of object using classloader like

this.getClass().getClassLoader().loadClass(com.amar.myobject).newInstance();

Now you know how to create an object. But its advised to create objects only when it is necessary to do so.

sampra

 Profile Answers by sampra Questions by sampra

• Mar 13th, 2012

There are 5 ways:
1-> new operaotor
2-> Class.forName()
3-> Cloning
4-> Deserialization
5-> Class.newInstance()

Max

• Sep 7th, 2011

All sorts of syntax sugar can also be named: 6. New String as a result of concatenation: String varName = getClass().getName(); //to avoid compile-time optimization String a = "Prefix" + varName; ...

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Can we make use of "this" keyword reference inside a abstract method or abstract class? Explain

java indian

 Profile Answers by java indian Questions by java indian

• Mar 10th, 2010

Yes we can use "this" key word in Abstract class or methods,Here we have simple sample used of this key in abstract.abstract class ab { int j;void  meth()  {  this. j=10; ...

yogesh249

 Profile Answers by yogesh249 Questions by yogesh249

• Jan 24th, 2010

Yes that is true that we cannot create object of an abstract class. But the question is "Can we use this keyword in an abstract class."The answer is YES we can..Have a look at the following ...

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JohnJosephKiernan

 Profile Answers by JohnJosephKiernan Questions by JohnJosephKiernan

• Jul 30th, 2006

Premm, see replies #20 and #21, and the JLS.If Java doesn't have pointers why are they mentioned in the JLS? and why does it have a NullPointerException?It doesn't have pointers with the semantics you describe: that's a different issue.IMHO what it doesn't have is *references* actually.

premmm

 Profile Answers by premmm Questions by premmm

• Jul 29th, 2006

Hi anupamaActually, java does not use pointers.s1 is an object.Let us consider the following situation.If you write username and password in your login page using pointer. go and see the view source o...

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smartcasanova

 Profile Answers by smartcasanova Questions by smartcasanova

• Jan 13th, 2010

Because of the promitive data types provided in the java such as int, char float, these primitives are not objects hence Java is not pure OO.

sahit

 Profile Answers by sahit Questions by sahit

• Oct 27th, 2009

Java does not support multiple inheritance as well as operator overloading, so we can say that Java is not completly supporting OOPs.

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Bhavesh

• Feb 28th, 2015

To get the hierarchy of classes that I might need later.

We dont want the user to know what functionality it offers other than some important We also dont want user to use reflection to exploit functionalities

punyamca

• Feb 6th, 2015

For late binding purpose. to design a method so that a part of functionality has to be mentioned by end user(implementing class)

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Karuna Reddy

 Profile Answers by Karuna Reddy Questions by Karuna Reddy

• Jun 5th, 2008

Rest of the two method to open it and close the braces.EX:interface in1{                public void A();   &nb...

Karuna Reddy

 Profile Answers by Karuna Reddy Questions by Karuna Reddy

• Jun 1st, 2008

public interface MyInterface1 { public void A(); public void B();public void C();public void D(); }package com.venkata.ust; public class MyClass1 implements MyInterface1 {  @Override pu...

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Jitendra singh

• Sep 23rd, 2015

Actually main reason that new make a class create only print my name not use object. You can create a simple program without using object this reason Java not 100% object oriented language {geshibot l...

SHWETHA g

• Aug 31st, 2015

"Static" keyword is used to a variable/method where a value of that variable has to be common to all objects created for example: bank interest rate for farmers loan common to all farmers.
where as "final" is to make a method or variable that should not be modified once after implementing.

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sampra

 Profile Answers by sampra Questions by sampra

• Mar 6th, 2012

HashMap is not collection inteface where as HashSet is Collection interface.
HashMap class implements Map interface where as HashSet class implements Set interface.
HashMap is prints the elements orderly where as HashSet has no order, if you need some order then go for TreeSet.

maheshjammula

• Nov 28th, 2011

HashSet and hashMap both are not maintained order.Difference is hashMap contains key value to map the corresponding value but hashSet have no key value and index value.Their implementations is another matter.

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public interface I1{Static String x="inside I1";public void someMethod();}class A implements I1{ public static void main(String args[[]){ System.out.println("Calling I1 var ..."+I1.x);}}

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abuthahir.d  

 Profile Answers by abuthahir.d Questions by abuthahir.d

• Member Since Jan-2008 | Apr 14th, 2008

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Compilation error due to 2 reasons.
1. All variables defined in the Interfaces are implicitly public static final. So need not specify "Static" in interface.

2. If any of the member functions of a Interface is not Overriden , a compilation error will be thrown

shanu_rastogi

 Profile Answers by shanu_rastogi Questions by shanu_rastogi

• Feb 3rd, 2010

It is right that you dont need to explicitly define a varible static but if you do so then it will not give compliler error..

sarojmohanty

 Profile Answers by sarojmohanty Questions by sarojmohanty

• Nov 19th, 2009

Compilation error will come because you must have to override the abstract method of the implememted interface. After the implementation of the abstract method the program will compile and run properly and print "inside l1".

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Which is faster at class loading - interface or abstract class? Why?

deshmukhcv

 Profile Answers by deshmukhcv Questions by deshmukhcv

• Jul 12th, 2010

I will give the Answer with Example : Where to use Abstrace Class ::Suppose I am having class Animal. and Dog Class and Cat Class. Animal Class having method eat(). In eat() I will writ...

abhijeetsingh

 Profile Answers by abhijeetsingh Questions by abhijeetsingh

• Jan 27th, 2010

In both cases differences will be negligible. It only depends upon our designing to use which one.

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If Exception occurs in finalize() what happened to garbage collector? It will run or not? Explain

raja_manoo

 Profile Answers by raja_manoo Questions by raja_manoo

• May 30th, 2010

Exception will be ignored...

asanse

 Profile Answers by asanse Questions by asanse

• May 27th, 2010

Any exception thrown by finalize() during garbage collection halts the finalization but is otherwise ignored.

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nnandurkar

 Profile Answers by nnandurkar Questions by nnandurkar

• Jun 23rd, 2010

Java supports only pass by value. If it is a primitive then copy of the value is passed. And if it is an object then copy of its reference is passed.

sampra

 Profile Answers by sampra Questions by sampra

• Feb 20th, 2008

In Java Object are passed by reference and Primitive data is always pass by value

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