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1. i++; vs ++i;
2. int j = i++; vs int j = ++i;">What's the "performance" difference between i++ and ++i? 2 senarios:1. i++; vs ++i;2. int j = i++; vs int j = ++i;
Y_NOT_
- Feb 6th, 2007
public class Increment{ public Increment() { int i = 0, j = 0; System.out.println( "1- j = " + j ); j = i++; // prints 0 but infact the value of j is 1. System.out.println( "2- j = " + j )...
agyeya
- Jan 12th, 2007
There is definitely no difference between ++i and i++ if they are used as statements on their own. Only the presence of an additional assignmentforces a difference in the compiled bytecode.In the cont...
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How can we call multiple applications using simple command in java
VenkitaKrishnan
- Apr 20th, 2009
Create a batch file and write down all the applications which needs to be called. Simple isn't it?
ramesh.sukka
- Apr 16th, 2009
Write Java Threading Application in which you can invoke multiple Java Application at time. so from Command promt if you execute Thead application, internally it will executed multiple application.Regards,Ramesh Sukka.
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(1)Can we have more than one connection object with database at same time?(2)Why Interfaces in JDBC have objects?
rammaheswara
- Aug 10th, 2009
Yes, we can have morethan one connection object same time. This is how we implement connection pooling. Poole minimum and maximum numebr of connections.
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What is the use of volatile and transient modifiers?
Sunny Jain
- Feb 28th, 2007
Volatile Variable: Whenever a variable is declared as volatile, the thread accessing the variable have to reconcile its copy of variable with the master copy of that variable....Transient:We can decla...
JavaStudent
- Feb 12th, 2007
Transient: The transient modifier applies to variables only and it is not stored as part of its object's Persistent state. These variables are not serialized. Transient instance fields are neither sav...
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How to design connection pool mechanism which is well suited in multithreaded environment
lhariPrasad
- Mar 18th, 2008
Remember these points while designing the connection pool mechanisim.1. Maintain a hash table of all the created connections2. Assign a flag status for each connection whether it is in use or free3. O...
sampra
- Mar 11th, 2008
In the connection poolin mechanism instead creating conig connection one by one we can create create lot of connection by the help of container there is two paramentre required 1.initial no of connection 2.max no of connection
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What is the difference between Apache Container and Apache Server
sampra
- Mar 11th, 2008
Apache server is an application where as apche container is a prog which is used to creeate the object
rajnish_j2ee
- May 10th, 2007
An Apache Server is basically a webServer and it may comes without the servlet container. So we can say Apache server that is a part of Apache container .
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How can we call a class in directory by a class in another directory by writing class paths
sreenivas reddy
- Nov 26th, 2007
We should set the class path otherwise we can't compile the java program.
kohina
- Nov 18th, 2007
Suppose 'A' directory has 'class x' and ' B ' directory has ' class y ' then while compling the x class give the classpath of class y . Even whi...
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What is whitespace in Java?
psuresh1982
- Oct 25th, 2007
Whitespace in Java is used to separate the tokens in a Java source file. Whitespace is required in some places, such as between access modifiers, type names and Identifiers, and is used to improve rea...
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In How Many ways can we create an OBJECT in Java ? Illustrate.
sampra
- Feb 14th, 2008
perfect ans:Here is the list I formed: 1) using new 2) Serilaization 3) Shallow cloning 4) Deep cloning ý same is serialization 5) Reflection/ Class.newInstance()
Sagar
- Nov 27th, 2007
Here is the list I formed: 1) using new 2) Serilaization 3) Shallow cloning 4) Deep cloning ? same is serialization 5) Reflection/ Class.newInstance()
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What is the need for calling default constructor by JVM? why the JVM should intiializes default values to the data fields if the constructor is not there in our class?
sampra
- Feb 14th, 2008
use of default constructor is to create the default object of type java.lang.Class which is done by JVM
Raghava
- Nov 20th, 2007
First, Let us understand the concept of construcotrs. The constructors are used to construct objects. This is the Only way to create object. If we did not write any constructor in our class, the compl...
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Can we declare an interface in servlet
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Why should we extend Exception instead of Throwable?
We usually extend Exception instead of Throwable. Why? In what situations we extend Throwable.Could anybody give the answer in detail. Thanks in advance.
shweta.suryanarayanan
- Oct 1st, 2008
By extending Throwable, you are giving hook for RuntimeException and programmers normally do not catch unchecked exceptions. However, if you have an app server and want to en...
rariedel
- May 27th, 2008
Extending the Exception class (a descendant of Throwable) instead of extending Throwable itself is a programming convention, not a requirement.Like most conventions, following the convention lends consistency to the end result.
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Difference between throw and throws
What exactly is the difference between between throw and throws? If both are used for the same purpose then why are both needed instead of one?
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Editorial / Best Answer
vegetto- Member Since Jun-2008 | Jun 15th, 2008
hi there,
throw:the throw keyword is used to throw the exception manually,that is when you feel a particular line in your code, when executed is capable of having some exception then you use throw keyword as:
throw new MyException(arguments if any);
this leads to instantiating of the MyException class and exception is thrown
throws: this is to be used when you are not using the try catch statement in your code but you know that this particular class is capable of throwing so and so exception(only checked exceptions).in this you do not use try catch block but write using the throw clause at appropriate point in you code and the exception is thrown to caller of the method and is handeled by it. eg:
void trouble()throws IOException,any other exceptions just separate them with commas.......
{
/* throw statement at appropriate step,
no need to use try catch here,exception would be thrown to caller and u should provide try catch block to handle exception there else this process cotinues further till
appropriately it is handeled or prog terminates abruptly */
}
this is called as HANDLE OR DECLARE RULE i.e either u handle exceptions using try catch block or by declaring them
vegetto
- Jun 15th, 2008
hi there, throw:the throw keyword is used to throw the exception manually,that is when you feel a particular line in your ...
krishna_kanth83
- Jun 14th, 2008
they are not same."throws" declares that your method is capable of throwing an exception."throw" actually does the work , of throwing the exception.example :public void...
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Read Number Methods
How many methods to read numbers and characters and what should be used.
Sarje
- Aug 17th, 2009
Methods in InputStream to read byte and in Reader to read character are -int read()int read(byte buffer[])int readIbyte burrer[],int offset,int numBytes)
inthiyaj
- May 9th, 2009
We have readers and streams. Readers are used to read characters and streams are used to read bytes, streams returns numbers i.e. byte number.
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Command prompt argument
How to pass commandline arguments in main function through Eclipse Tools (editors).
nookashiva
- Sep 14th, 2008
Click the Run menu barNow click the Open Run DialogueA new window will be opened.In that window click the Java applications thenA new sub menu will be opened in that select Arguments menu andType the Arguments with space.Click run to view your result in the console.
Gokul44
- Jul 18th, 2008
Click the run menu barnow click the openrundialoguea new window will be opened.in that window click the arguments menu and type the arguments with space.click run to view ur result in the console.
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What is the purpose of singleton design pattern?
mani.sivapuram
- Feb 10th, 2011
Singleton design pattern is used to create only one instance.I want to a an example when we are using this singleton design pattern in real life.generally the dao classes like insertDao,updateDao,dele...
shreesha.s
- Sep 5th, 2010
Singleton Design Pattern is used when we would like to have a single instance. A class distributes the only instance of itself. It will be used with Connection Pool usually.
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Overloading Performance
If Overloading is not going to help to increase performance then why we need to use same name for different methods?
mohit235
- Dec 28th, 2010
Their is no such use for programmer, their is signifigance for user, he/ she has no need to know and remember a lot of method name, one can do different work.
ajay8706
- Nov 27th, 2010
By using Overloading, we implement Polymorphism in Java that is why same mehods can act as differently in situations by using overloading.
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Create Object Using Clone
Give an example of using clone to create an object.
muralidhar.9e
- Oct 11th, 2010
We can create an object by using clone() method which is a object class method.Create an object like MyClass obj=new MyClass();CloneClass cloneobj=(CloneClass)obj.clone();By this way you can create a ...
Core Java Interview Questions
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