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What is the order of intialization of variables in Java.
muralidhar.9e
- Sep 8th, 2010
In Java the variable initialization should be in order. The order is: 1. Static block variables initialize at first 2. Static method of variables initialize second 3. Static variables initial...
sampra
- Feb 15th, 2008
First of all declare a memory block according to data typeassign var nameinitite by def valuewassign orignal value
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What is the difference between Inheritance and Aggrigation?
vinaymudgil007
- Mar 21st, 2011
Inheritence means --> "is-a" relationshipe.g. HONDA CITY is-a CARAggregation means --> "has-a" relationshipHONDA CITY has-a engineHope this makes it clear !!!
navneetgoyal2000
- Jan 5th, 2011
If we have to explain it with example, then Inheritance (IS A or TYPE OF) & Aggregation (HAS A) can be understood as:a CAR IS A (an) Automobile. (Inheritance: Car inherits its properties from Automobile)Whilea CAR HAS A (an) engine. (Aggregation: Car Class has an Object of engine class)
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What are some alternatives to inheritance?
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What is serilization and deserilization
sampra
- Feb 22nd, 2008
Taking object state in flat file is serilization where as reconstructing new obj wt that data is deserlization
sujatham
- Aug 2nd, 2007
To serialize an object means to convert its state to a byte stream so way that the byte stream can be reverted back into a copy of the object. A Java object is serializable if its class or any of its ...
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//this.disp();
}
void t3()
{
System.out.println("Enter to t3 void");
}
}
On what situation void type constructors are used?">Class t3{ int i; static public void main( String a[]) { int j=8; t3 t= new t3(); new t3().disp(j); } //constructor overloading t3() { System.out.println("Enter to t3"); //this.disp(); } void t3() { System.out.println("Enter to t3 void"); }}On what situation void type constructors are used?
vinaymudgil007
- Jun 12th, 2008
Constructor's don't have any return-type....... and hence when you precede void with constructor java comipler treats it as a METHOD of that class and not as constructor!!!vinny
chinnu
- Nov 18th, 2006
Actually constructor means one type of special methods in java. It returns nothing even void also. These are used for intilising the objects with same parameters and different parameters.
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Why class Class is always the Super Class for every class
ashish
- May 20th, 2012
1. Object is super class for all java classes.
2. even if someone want to make a class as subclass of CLASS class, he cant because class class is declared as final. so it can not be inheritedvinaymudgil007
- Jun 12th, 2008
Java.lang.Object is the super class of all classes and NOT Class classvinny
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Which marker interface in java is having methods in it
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Market interface means interface which have no methods. Then why we call the Runnable interface as a marker interface, even though it has run() method
pdommara
- May 31st, 2010
Who said Runnable interface is marker interface. It has method called run(). It is not a marker interface.
piscesinblues
- Jan 22nd, 2007
Up to my knowledge marker interface is an interface having no methods, so Runnable interface is an interface having run() method, so definetly it is not a marker interface, if so the case, please post the complete description regarding that and let me know
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Where Scanner Class used in JAVA?
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Why Hash table doesn't allow null values as well as null keys?
Vinay Kumar
- Nov 23rd, 2015
Hashtable is a legacy class. hash table doesnt allow duplicate object as a key and value beacause hashtable implements hashcode () method. Hash code method compute object hashcode number if object is ...
Subbarayudu Golla
- Jan 18th, 2011
HashTable:1.) From the APIs, we can see, the objects which stored in the Hashtable should implement hashCode() and equals() methods. 2.) To successfully store and retrieve objects from a hashtable, th...
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What is the difference between abstract and final classes?
sampra
- Feb 15th, 2008
Abstrct class has some method who has no body so we cant create object for that whaere as fianal class is lik constant class we cant change the class ie we cant extend the final class so if we have to make anny class as immutable then declare class as final
sujatham
- Aug 10th, 2007
1. Abstract class cannot be instatianted.But final class can be instatiated.2. Abstract class must be etended. But final class cannot be extended.3. If we declare class as final,then that class canno...
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Which one is better when compare with Interface and Abstract class ?
muralidhar.9e
- Oct 30th, 2010
I prefer to Interface. Because the same feature can have different implementations in different Objects.And can also support for multiple Inheritance through Interfaces.If you go for Abstarct Classes ...
salman138
- Oct 29th, 2010
Both Interface and Abstract class have different usages. Interface is used to define that an object support a certain kind of functionality like any class that implements Comparable interface has the ...
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What is the practical use of volatile / transient modifiers?
naresh17201
- Jul 21st, 2010
Transient variables are can not be serialized. So it is used in the serialization process.In serilization object, some field is marked as transient,will not be transmitted in the byte stream.eg..file ...
mharivardhan
- Jul 15th, 2010
Volatile: In a multithreaded scenario when a shared variable value is modified by Thread1 might not be immediately updated to main memory. When Thread2 reads, it will get the old value. You...
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What do you meant by private constructor? why somebody declare only private constructor.
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How hashtable is synchronized?why hashmap is not synchronized?Can we make hashmap synchronized?
karthi1106
- Dec 10th, 2009
Vector/Hashtable Original classes before the introduction of Collections API. Vector & Hashtable are synchronized. Any method that touches their contents is thread-safe. ArrayList/HashMap So...
ssubhajit
- Nov 25th, 2009
Use the Code below to make a Hashmap synchronized ...Hashmap objHashmap = Collections.synchronizedMap(new HashMap(....));
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Meaning - Abstract classes, abstract methods
jawaharl0207
- Oct 25th, 2009
Abstract Class: There are two ways to create abstract class, one is by mentioning abstract key before the class declaration, and second one is by mentioning abstract key before the method declaration ...
haruto
- Oct 22nd, 2009
In java a class has a well defined structure and behaviour. There are times where we do not need to implement a method such methods are written in the class where the class is preceded by keyw...
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