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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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When will we go for abstract class and when will we go for interface?
Praveen Kumar Singh
- Mar 13th, 2012
When you have some methods to be implemented as common and some methods you want to keep abstract, that time we will go for abstract class. You want to provide contract between class and object. And you don't want to implement any method as common that time we will go for interface.
sampra
- Mar 6th, 2012
Correct ans would be:Whenever there is need of having same common features among all subclasses of super class, we have to go for an abstract class.
Whenever there is no common features for subclasses of super class, we have to go for an interface.
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What is heap in Java
Debananadajena
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HiHeap is the location where a object is stored after it is instansiated.Means after A obj=new A();now obj will be storeed in heap.
sampra
- Feb 22nd, 2008
It is a memory area which stores all the objects created by an executing program.
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A static member class or a static member interface comprises the same declarations as those allowed in an ordinary top-level class or interface. A static member class must be declared as a static memb...
sameer.s.abdeen
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A static inner class is a static member of the enclosing classclass BigOuter{ static class Nested{}}A static inner class has no access to instance variables and non static members of the enclosing class
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Two kinds of exceptions:unchecked exceptions and checked exceptions.Inside the standard java.lang package ,Java defines several exception classes.Most of the exceptions are subclasses of standard type...
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In a bytecode-compiled system, source code is translated to an intermediate representation known as bytecode. Bytecode is not the machine code for any particular computer, and may be portable among co...
sampra
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It is essential to catch all types of exceptions
Visithra.G
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It is essential to catch declare throws clause for checked exceptions unchecked exception need not be handled.
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What is the difference between ArrayList and Vector otherthan arrayList is not synchronised but Vector is?
sampra
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sujatham
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1. In vector the data is retrieved using the elementAt() method 2. In ArrayList, it is done using the get() method. 3. ArrayList has no default size while vector has a default size of 10.?4. ArrayLi...
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The main reason is Inheritance. If you observe the methods in Object class, contains the basic methods that every class should contain and they are very basic features or functionalities that every class should have and support.
Also there are many reasons for that...jawaharl0207
- Oct 22nd, 2009
Because it has methods like useful for all the classes, like wait, notify, notifyall, clone and gc, these methods are common use for all classes.
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1. Encapsulation means Binding the Data with its relative functions. That means only those functions can access the data, and no other function can access that data. This can be achieved by classifyin...
lhariPrasad
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Venkat,The thing which you mentioned can also be done by Inheritance, then what is the need of Abstraction over here in Java. Is it that much important ?I feel Abstraction is something where a specific template like structure is created for the implementators, aiming to provide a common interface.
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Primitives are always passed by value.Objects: Passed by value of reference. i.e. a copy of reference is passed into the method. Any changes to the reference itself will not be visible outside the met...
Scorpio_
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Mr Ashutosh Gupta,Java is pass-by-value. For primitives, you pass a copy of the actual value. For references to objects, you pass a copy of the reference. You never pass the object. All objects are stored on the heap. Always http://www.javaranch.com/campfire/StoryPassBy.jsp
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umesh_kilkile
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ravikumar_kapala
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Dear sabrik , we cannot call any method from the constructor . Please check your answer and correct it accordingly.
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> StringBuffer have synchronized methods. String have unsynchronized methods.So one can use StringBuilder in Java 1.5
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