Java collections Interview Questions

Java Collections is the type of the set of classes that help to implement the common reusable data. Java Collections framework is one of the most important parts of the Java programming language. Java Collections is the type of containers that help you group all the types of multiple items in the single units. The collection in Java is mainly a type of framework that helps to provide an architecture to store and manipulate all the other group of the objects. Java Collections will help you to achieve all the operations that one can perform on the data. This type of operations includes searching, sorting, inserting, manipulation and deletion. There are some of the Java Collections interview questions and answers that will help you a lot.

The Java Collections basically means the single units of the objects. Java Collections framework also provides several types of interfaces and the classes. In the Java Collections framework, the collection interface and the map interfaces are the most important types of the Java Collections classes. Below are some of the Java Collections interview questions and answers.

#1 What is the use of the list interface in the Java collection?

The main use of the list interface is to allow the Java Collections to define an ordered collection with the duplicates. The list interface helps to add all the position-oriented elements and the new list Iterator that will help to enable the list to become bi-directional.

#2 What are the different types of features of the Java Collections framework?

The following are some main features of the Java Collections framework:

  • Deque has the feature to provide the support of the resizable array and will also help to free the array so that the array can grow according to the usage.
  • Any of the concurrent access is not being supported by the multiple threads or the Deque.

#3 What are maps interfaces in the Java Collections?

A map is basically a type of container that stores the elements along with the keys in the Java Collections. These types of keys are basically indexes. In the map interfaces, the keys can be of any of the objects. A map doesn’t contain any of the duplicate keys.

#4 What are the classes in the Java collection framework?

The classes in Java are generally the types of application or the collection of the interface. These types of classes mainly refer to the data structure that is used again and again.

#5 What are the uses of the set interfaces in the Java Collections?

The main work of the set interface is to extend the Java Collections framework. At this moment, it will also make sure that if there is any of the duplications of the elements.

#6 What are the main classes of the list interfaces?

The following are some of the main classes of the list interfaces:

  • Stack
  • Vector
  • Array list
  • Linked list

#7 What are the queues in the Java collection framework?

A queue is basically a first in and first out data structure. The elements are basically are added at the end of the queue and are automatically removed from the starting of the queue.

#8 What are the types of interface used in the Java collections?

The following are some of the types of interfaces used in the Java collection and they are:

  • Collection interface
  • List interface
  • Set interface
  • Queue interface
  • Dequeue interface
  • Map interface

#9 What are the different types of classes implemented in the Set interfaces?

The following are some of the classes implemented in the set interfaces:

  • Enum set
  • Hash set
  • Linked Hash set
  • Tree Set

#10 What are the types of the main implementing classes in the map interfaces?

The following are some of the implementing classes in the map interfaces:

  • Hash Map
  • Hash table
  • Enum Map
  • Identity Hash Map
  • Linked Hash map
  • Properties

#11 What is Java Collection?

A Java collection is a group of individual types of objects that are represented in a single unit. Java also helps to provide the different collections of the framework which helps to define different classes and the interfaces to represent all the group of objects in a single unit.

#12 What is Deque in the Java Collections framework?

Deque is the type of the double-ended queue that basically helps and supports the addition and removal of the elements from either end of the data structure.

#13 What is an algorithm in Java Collection Framework?

The algorithm in the Java Collections framework refers to the methods that are used to prefer various types of operations. This includes searching and sorting of the objects that help to implement the collection interfaces.

#14 What are the types of Java Collections?

The following are some of the types of the Java Collections:

  • Interfaces
  • Classes
  • Algorithm

#15 What are the differences between the Java collection and the Java list?

Java CollectionJava List
Java Collections is just a type of a collection of items in which you can add, remove, iterate and also can have the query about how much stuff is being collected in Java.A Java list basically adds information about the defined sequences of all the stuff that are being present in it.
The collection is basically a root interface of Java.A list is one of the subinterfaces that mainly helps to define an ordered collection.
Ask a Question