Java Collection Framework Most Important Questions

  Java Collection Framework Most Important Questions

 

Q:-1   What is Collection Framework ?

A:-     Collection framework is a unified architecture or predefined java classes and interfaces that is used for implementing  a group

         of objects in java.

Q:-2   What is Collection ?

A:-     A collection represents a group of objects. And it is root interface of java collection hierarchy.

Q:-3   What is Collections ?

A:-     Collections is a utility class in java which is present is java.util package for manipulating  data. It provides static method for   

         searching, sorting and more.

Q:-4   What is difference between Array and Collection ?

A:-

               Array                                                                            Collection                                                

 

 1>     Array is a object in java which                    Collection is a interface which contains    

           contains similar data elements.                   methods for implementing classes and basic

                                                                             operations.

 2>    It contains elements in a specified              It  is growable in nature so it can be increase its

          limit.                                                            size when required.    

 3>    Array is best suitable when data is             Collection is best suitable when data size is unknown.

         fixed in size.                  

 4>    Array can contain same type of data.          Collection can contain different types of data.

 5>    It doesn't provides basic operations            It provides basic data operation methods like

         method support.                                          add, addAll, remove and more.

                                                                                                                                                                                                                                                                                                                                                           

 

Q:-5   What is List ?

A:-     List is a child interface of collection interface. List interface is implemented by using dynamic                 array data structures. It can contains duplicate data.    

Q:-6   What is Set ?

A:-     Set is a child interface of collection interface. Set interface is best suitable when duplicate

          data not required.

Q:-7   What is Queue ?

A:-      Queue is child interface of collection interface. Queue interface is best when data processing 

          is required in prior to processing. It follows FIFO order i,e First in First Out order.

Q:8    What is ArrayList ?

A:-     ArrayList is a class in java. That implements List interface. It provides random access of data                   elements. we can access elements from ArrayList like an array.

Q:9    What is LinkedList ?

A:-     LinkedList is a java class that implements List interface. Data stored in linkedList of the form

           of node. Data insertion operations are fast in linkedList.

Q:10   What is Vector ?

A:-      Vector in java is a class which implements List interface. It is also known as legacy class 

           because it present in java from java 1.0 V. It uses dynamic array. It is same as arrayList 

           except, arrayList is non-synchronized and vector is synchronized.