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What are the Non access modifiers?
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Please give me answer why we use Interface though it contain only blank implementation.
muralidhar.9e
- Sep 20th, 2010
An Interface may Contain implementation or not. Sometimes these type of interfaces (blank interfaces) which are not implemented are called as "marker interfaces".
nikhil_52001
- Sep 19th, 2010
The purpose of Marker interface is to just let the compiler know that the clas which implements the Marker Interface will be serialized or cloned. Ther is not any other use of Marker Interface. E.g If...
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Remove() method collection
Which Underlying Collection will provide the remove() method?
rariedel
- May 28th, 2008
Collection is an interface, and whatever class implements the interface must implement the remove() method.This question is not a complete sentence and that makes it kind of difficult to understand the intent and then answer it appropriately.
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WeakHashMap
Explain how a WeakHashMap works?
aryadipan
- Sep 19th, 2010
You put an entry in a WeakHashMap with the object as the key, and the extra information as the map value. Then, as long as you keep a strong reference to the object, you will be able to check the m...
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What is the difference between Static and Dynamic Polymorphisim?
pradeep_gupta49
- Sep 16th, 2010
First of all I am telling about Polymorphism Polymorphism: The term polymorphism was defined from the greek 'Poly' and 'morphos' which mean 'many' and 'forms'. Poly+Morphos=Many forms Polymorph...
bhaumiklitu
- Jan 5th, 2009
The term static polymorphism is associated with overloaded methods because it gives the impression that a single named method will accept a number of different argument types. The System.out.println()...
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J2EE Code Standards
What are the code standard used in J2EE project in real time?
thimothyarani
- Sep 16th, 2010
Give proper name for the variable, it has to describe it functions or process. Follow coding standards
Sriram_Geek
- Aug 15th, 2010
1) Give meaningful comments.2) Give meaning variable names.3) Use lazy initialization of variables that is declare them as and when needed. Need not declare variables upfront like in C.4) Make sure yo...
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How to create own Marker Interface with example
nagarajcse82
- Nov 28th, 2005
1.>in general tagged or marker interface is used to just identify the class, in real time projects there are so many classes,in order to identify which class belongs to which module,this tag or mar...
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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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ReadLine() Function
Explain readLine function in Core Java.
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omkar.raj- Member Since Jul-2010 | Jul 8th, 2010
ReadLine() function is used to take the input from user in string format.
muralidhar.9e
- Sep 8th, 2010
Actually the readLine() method will reads the data through the bufferdReader object. It reads only one line of data through keyboard. We can't enter the multiple lines of data at runtime.This is the main functionality of the readLine() method.
sailendra.n.jena
- Aug 26th, 2010
It will read the data from the keyboard but line by line not character by character.
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What are some alternatives to inheritance?
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How to Synchronize the HashMap
Any Body Tell about this
pitu2000
- Aug 21st, 2010
After introduction of concurrency api in Java 1.5 we have one more way to synchronize a hashmap>> new java.util.concurrent.ConcurrentHashMap(hashmapObj);
EshaPrasad
- Apr 21st, 2009
We can do as given belowHashMap hm = new HashMap(); HashMap hm2 = (HashMap)Collections.synchronizedMap(hm); ArrayList a1 = new ArrayList(); ArrayList a2 = (ArrayList)Collections.synchronizedList(...
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IBM Interview Questions in Bangalore
Br />1.what is oracle.2.what is major differenece oracle8i and oracle9i.4.tell me some thing ur self.5.please tell me about oops.6.what is single inheritance.7.what is multiple inheritance.8.can java support multiple inheritance.9.what is interface.10.what is differenec between abstract class and interface.11.how to u prove that abstrace class cannot instantiate directly.12.what is differenece between...
sujain
- Aug 17th, 2010
5. About OOPS: Object Oriented Programming is based on three major concepts: Inheritance, Polymorphism and Encapsulation Inheritance: Through inheritance the base class properties are acquired in subc...
anithananduri
- Aug 28th, 2009
8.can java support multiple inheritance.java support multiple inheritance for interfaces not fro classes25.what is difference between procedure and functions.function returns only one value where as procedure returns more than one value
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Would you like to derive data from a base class
biman786
- Aug 14th, 2010
If the Base class and super class are within same package, then data of super class should be public or default or protected. But if base and super classes are in different packages, then?then data of super class should be public or protected.
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Arrays/Linked List
When and on what conditions will you decide whether to use linked lists or arrays, also Which process is fastest and which is slowest in arrays as well as linked list i.e, sorting, searching, add, delete etc.
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Aqan12- Member Since Apr-2010 | Jun 13th, 2010
Memory:
When you create an array you allocate all the memory while initializing the array, so if you had an array of 1000 Objects, you'd allocate space to hold 1000 object references as soon as you initialize the array.LinkedList on the other hand extends dynamically as the objects are added to the linked list.
Accessing Elements:
Arrays are useful if you are going to access elements using the index. if you need to access the 100th element you can directly access it by a[100].To access 100th element in a LinkedList you'll have to traverse 99 elements to reach the 100th element.
LinkedList can handle addition/deletion of elements better then arrays and that's one of the most powerful feature of LL over arrays.
Adding/Inserting Elements:
Array is fixed size; to add a number of elements greater then the size of the array you'd have to copy the array into a new bigger array.To insert an element in the middle of an array all the elements after the inserted element would have to moved up one index.
LinkedList can grow dynamically.
Deleting Elements:
To delete an element from Array you'd have to move down all the elements after the deleted element.LinkedList elements can be deleted dynamically.
To summarize, LinkedList can handle manipulation of data structure much better and efficiently manage memory but arrays have better accessibility when accessing elements by index.
Search and Sort would be similar performance on both.jamesjohnney
- Aug 12th, 2010
In all way Linked list is best then Arrays, since its a next level of Array 1. Linked list is dynamic allocation where as Arrays are not 2. We can get and set the value with the use of get, set method...
Anubhavs
- Aug 6th, 2010
Linked list is best under the feature of the manipulation e.g. insertion, deletion etc. In the other way the array will go through a good way if we focus on the accessibility.
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Jumble Array Values
An array A is of size N. Write a java method that jumbles all values in the array. All possible permutations must be possible and chances for each possible permutation must be equal. For example, size of array A is 3. A[0]=x, A[1]=y, A[2] =z.Possible permutations are 3! After jumbling elements, there would be equal chances for each of xyz,yxz,... to be in the array elements.
n_ulthi
- Aug 6th, 2010
public class Shuffle { // swaps array elements i and j public static void swap(String[] a, int i, int j) { String swap = a...
sandeep aulakh
- Dec 2nd, 2009
Class jumble{public stativ void main(String aa[]){int a[]=[1,2,3];for(i=0;i<3;i++)for(j=0;j<3;j++){a[i][j]=a[j][i];}System.out.println("the result is"+a[i][j]);}
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How do you declare constant values in java
rohitrichhariya
- Jul 23rd, 2010
For declaring constant in Java, Java gives us 3 suggestion.1. Declare constant variable as a final.2. Also constant variable declare as a final.3. All the letter of constant variable is capital....
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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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Abstract vs Interface Class
Which is faster at class loading - interface or abstract class? Why?
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
- Jan 27th, 2010
In both cases differences will be negligible. It only depends upon our designing to use which one.
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What is the meaning of System.out.println(). How it is constructed?
satvant sandhu
- Jul 4th, 2010
System is only class which intracts with hardware and out is static reference variable of PrintStream class and println() is a method of PrintStream class.it's construction is like that...class&nb...
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In Java, how are objects / values passed around
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
- Feb 20th, 2008
In Java Object are passed by reference and Primitive data is always pass by value
Core Java Interview Questions
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