Tuesday, 1 May 2012

JAVA interview questions 34

Q331. What is Collection framework? 
It defines set of classes and inter faces which can be used for representing a group of objects as single entity 

Q332. What is difference between Collections and Collection? 
Collection is an interface which can be used for representing a group of individual objects as single entity and it acts as root interface of collection frame work. 
Collections is an utility class to define several utility methods for Collection implemented class objects. 

Q333. Explain about Collection interface? 
* This interface can be used to represent a group of objects as a single entity. * It acts as root interface for entire collection framework. 
* It defines the most commonly used methods which can be applicable for any collection implemented class object 
Q339. Explain about List interface? 
List interface is a child interface of Collection interface. This can be used to represent group of individual objects in as a single entity where 
* Duplicates are allowed 
* Insertion order is preserved 

Q334. Explain about Set interface? 
Set is a child interface of Collection interface. it can be used to represent a group of individual objects as a single entity where 
* Duplicate objects are not allowed. 
* Insertion order is not preserved 

Q335. Explain about SortedSet interface? 
it is child interface of Set interface. it can be used to represent a group of individual objects in to a single entity where 
All the objects are arranged in some sorting order (Can be natural sorting order or customizede). 
Duplicates are not allowed. 

Q336. Explain about NavigableSet ? 
It is child interface of SortedSet and provides several utility methods for navigation purposes 
It doesn’t allows duplicates 
Insertion order is preserved 
It is introduced in 1.6 version 

Q337. Explain about Queue interface? 
If we want to represent a group of individual objects prior to processing, then we should go for Queue interface. It is child interface of Collection interface. 
It has introduced in 1.5 version. 

Q338. Explain about Map interface? 
Remember it is not a child Interface of Collection Interface and hence Map and Collection Interfaces doesn’t have any relationship. 
It can be used for representing a group of Objects as key, value pairs. Both keys and values should be objects 
Keys can t be duplicated but values can be duplicated. it has introduced in 1.2 version 

Q339. Explain about SortedMap ? 
If we want to represent a group of objects as key value pairs where all the entries are arranged according some sorting order of keys then we should go for SortedMap. It is child interface of Map. 
It has introduced in 1.2 version 

Q340. Explain about NavigableMap? 
It is child interface of SortedMap and defines several method for navigation purpose It is introduced in 1.6 version

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