EDUCBA

EDUCBA

MENUMENU
  • Free Tutorials
  • Free Courses
  • Certification Courses
  • 600+ Courses All in One Bundle
  • Login

Data Structure Java Interview Questions

By Priya PedamkarPriya Pedamkar

Home » Software Development » Software Development Tutorials » Java Tutorial » Data Structure Java Interview Questions

Data Structure Java Interview Questions

Introduction to Data Structure Java Interview Questions and Answers

A data structure is an important building block of computer programming. It is the most basic and fundamental concept that every programmer or developer starts with when they decide to learn to programme or choose to programme as hoppy or career option.

For Java programming language, application of data structure is huge in any project, solution or product. The success of a product, scalability, and extensibility of its scope is highly dependent on the type of data structure chosen for various tasks and components during software development.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

In this Data Structure Java Interview Questions article, we shall provide important data structure questions to help candidates improve his/her skill on a subject.

Now, if you are looking for a job which is related to Data Structure Java then you need to prepare for the 2020 Data Structure Java Interview Questions. It is true that every interview is different as per the different job profiles. Here, we have prepared the important Data Structure Java Interview Questions and Answers which will help you get success in your interview.

In this 2020 Data Structure Java Interview Questions article, we shall present 10 most important and frequently asked Data Structure Java interview questions. These interview questions are divided into two parts are as follows:

Part 1 – Data Structure Java Interview Questions (Basic)

This first part covers basic Interview Questions and Answers.

Q1. How do you find middle element of linked list in one pass?

Answer:
In order to find middle element of linked list in one pass, one needs to maintain two-pointer. One of these pointers will increment at each node while other will increment after two nodes at a time, thus by having this type of arrangement, when the first pointer reaches the end of the linked list, the second pointer will point to a middle element of the linked list.

Popular Course in this category
Java Training (40 Courses, 29 Projects, 4 Quizzes)40 Online Courses | 29 Hands-on Projects | 285+ Hours | Verifiable Certificate of Completion | Lifetime Access | 4 Quizzes with Solutions
4.8 (8,993 ratings)
Course Price

View Course

Related Courses
JavaScript Training Program (39 Courses, 23 Projects, 4 Quizzes)jQuery Training (8 Courses, 5 Projects)Free Java Online CourseJavaFX Training (1 Courses)

Q2. How to know if a linked list has a loop?

Answer:
If two pointers are maintained, and one of them is incremented after processing two nodes and other after processing every node, it is likely that we find a situation where both the pointers are pointed to the same node.
This happens only if a linked list consists of a loop or cycle.

Let us move to the next Data Structure Java Interview Questions.

Q3. How to identify the third element from the end in a linked list in one pass?

Answer:
If the same trick as above of maintaining two pointers is applied where one pointer increments, when first has moved up to the 3rd element, then in that case when the first pointer reaches to the end of the given linked list, the second pointer will be pointing to the 3rd element of the list from last.

Q4. How to find a duplicate number in an integer array between 1 to 100 number?

Answer:
This is the common Data Structure Java Interview Questions asked in an interview. To get the answer, one can simply add all numbers stored in that particular array, and the total sum should be equal to n(n+1)/2. After this, one should subtract actual sum to the expected sum, and that is how duplicate numbers can be found.

Q5. How to reverse String in Java language?

Answer:
There are many ways available to reverse Sting in Java or other programming languages, one could do so by using built-in functions such as reverse() from StringBuffer class.

Part 2 – Data Structure Java Interview Questions (Advanced)

Let us now have a look at the advanced Interview Questions and Answers.

Q6. Describe some of the operations that are performed on different Data Structures?

Answer:
Operations that can be performed on data structures are as below:

  • Insertion: This is used to add a new data item in the existing set of data items.
  • Deletion: This is used to delete an already available data item from the existing set of data items.
  • Traversal: This can be used to access each data item only once before it is processed.
  • Searching: This can be used to find out the location of the data item if that particular item exists in the given collection of data items.
  • Sorting: This one is for arranging the data items in some order such as in ascending or descending order if numerical data and in dictionary order if alphanumeric data.

Q7. What do you understand by a Linked List and What are its different types?

Answer:
A linked list can be regarded as a linear data structure, where each element is a considered as a separate object or entity in itself. Each element within a list consists of two items – the data and the reference to the next node.

Types of Linked List:

  • Singly Linked List: In a singly linked list, every node stores two information. One is the address of the next node and other is data. the last node has NULL.
  • Doubly Linked List: In a doubly linked list, there are two references to each node, reference to next node and to the previous node.
  • Circular Linked List: In circular linked list all nodes are connected to each other and hence no NULL at the end. A circular linked list can be singly circular or doubly circular.

Q8. What do you understand by Data Structure?

Answer:
A data structure can be considered as a way of organizing the data for efficient utilization.

For example, Binary trees are particularly suited for database implementation, while compiler implementations are usually done using hash tables to look up identifiers.

Q9. What are linear and non-linear types of data Structures? Also, How is an Array different from Linked List?

Answer:

  • Linear: A data structure is called as linear if its elements form a sequence or a linear list such as Array, Linked List, Stacks, and Queues.
  • Non-Linear: A data structure is called as non-linear if traversal of nodes is of nonlinear nature such as Graphs and Trees.

Difference between array and linked list are the following: –

  • The size of the arrays is fixed always, Linked Lists size is not fixed.
  • Insert and delete in an array is an expensive process, whereas the same can be easily done in Linked Lists.
  • Accessing an element randomly is not possible in case of Linked Listed, but possible in an array.
  • Extra memory space for a pointer is needed with each element of the Linked list, arrays don’t have pointers.
  • Arrays have better cache locality mechanism that can make a big difference in performance.

Q10. What do you understand by Stack and where can it be used?

Answer:
This is the most popular Data Structure Java Interview Questions asked in an interview. A stack can be understood as a linear data structure which uses the order LIFO (Last In First Out) or FILO (First In Last Out) for accessing its elements. Basic operations on a stack are: Push, Pop and Peek

Applications of Stack are following:

  • Infix to Postfix Conversion can be done using Stack.
  • Evaluation of Postfix Expression is also possible.
  • Reverse a String using Stack can be done.
  • Implement two stacks in an array is also a nice use case.
  • Check for balanced parentheses in an expression is done using stacks.

Recommended Articles

This has been a guide to the list of Data Structure Java Interview Questions and Answers so that the candidate can crackdown these Data Structure Java Interview Questions easily. Here in this post, we have studied top Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –

  1. Java 8 Interview Questions
  2. Java Interview Questions
  3. Java Servlet Interview Questions
  4. Java Web Services Interview Questions

Java Training (40 Courses, 29 Projects, 4 Quizzes)

40 Online Courses

29 Hands-on Projects

285+ Hours

Verifiable Certificate of Completion

Lifetime Access

4 Quizzes with Solutions

Learn More

0 Shares
Share
Tweet
Share
Primary Sidebar
Java Tutorial
  • Interview Questions
    • Java Interview Questions
    • Java Inheritance Interview Questions
    • Java EE Interview Questions
    • Java Developer Interview Questions
    • Java Collection Interview Questions
    • Java Interview Question on Multithreading
    • Java String interview question
    • Java Testing Interview Questions
    • Java Multi-threading Interview Questions
    • Multithreading Interview Questions in Java
    • Oops Java Interview Questions
    • Java Spring Interview Questions
    • Data Structure Java Interview Questions
    • Java Web Services Interview Questions
  • Basic
    • What is Java?
    • What is JNDI in Java
    • What is JNI in Java
    • What is Java Interface
    • What is Java SE
    • What is JavaBeans
    • Install JDK
    • Java Programming Language Features
    • Applications of Java
    • Career in Java
    • Versions of Java
    • Java Virtual Machine
    • Java GUI Framework
    • Java Packages
    • Java Package Example
    • Default Package in Java
    • Variables in Java
    • Instance Variable in Java
    • Object in Java
    • Java Commands
    • Iterator in Java
    • Java Booleans
    • Conversion in Java
    • Type Conversion in Java
    • String in Java
    • What is JDK
    • What is JVM
    • What is J2EE
    • RMI Architecture
    • Java Literals
    • Data Types in Java
    • Primitive Data Types in Java
    • Enumset in Java
    • Cheat Sheet Java
    • IntelliJ Cheat Sheet
  • Frameworks
    • Best Java Compilers
    • Frameworks In Java
    • Testing Frameworks for Java
    • Java Monitoring Tool
    • Best Java IDE
    • Java Compilers
    • Java Tools
    • Java Deployment Tools
    • Types of Memory in Java
    • Java References
    • Java Type Inference
    • Java Boolean to String
    • Java String to Float
    • java.net Package
    • Java Formatter
  • Operators
    • Arithmetic Operators in Java
    • Unary Operators in Java
    • Logical Operators in Java
    • Comparison Operators in Java
    • Assignment Operators in Java
    • Java String Operators
    • Conditional Operator in Java
    • Boolean operators in Java
  • Keywords
    • Java Keywords
    • this Keyword in Java
    • Static Keyword in Java
    • Native keyword in Java
    • Throw Keyword in Java
    • Throws Keyword in Java
    • What is public in Java?
    • Private in Java
    • Protected Keyword in Java
    • Final Keyword in Java
  • Control statements
    • Control Statement in Java
    • Else-If Statement in Java
    • Nested if Statements in Java
    • Continue Statement in Java
    • Break Statement in Java
    • Case Statement in Java
  • Loops
    • Loops in Java Programming
    • For Loop in Java
    • While Loop in Java
    • do-while loop in Java
    • For-Each loop in Java
    • Nested Loop in Java
  • Inheritance
    • Inheritance in Java
    • Single Inheritance in Java
    • Multilevel Inheritance in Java
    • Hierarchical Inheritance in Java
    • Hybrid Inheritance in Java
  • Constructor and destructor
    • Constructor and Destructor in Java
    • Constructor in Java
    • Destructor in Java
    • Copy Constructor In Java
    • Static Constructor in Java
    • Private Constructor in Java
  • Array
    • Arrays in Java Programming
    • 2D Arrays in Java
    • 3D Arrays in Java
    • Multidimensional Array in Java
    • Array Methods in Java
    • Print 2D Array in Java
    • Print Array in Java
    • String Array in Java
    • Associative Array in Java
    • Dynamic Array in Java
    • Java Array Iterator
    • Java array.push
    • Sort String Array in Java
  • Sorting
    • Sorting in Java
    • Sorting Algorithms in Java
    • Merge Sorting Algorithms in Java
    • Quick Sorting Algorithms in Java
    • Selection Sort In Java
    • Heap Sort In Java
    • Bubble Sort in Java
    • Merge Sort In Java
    • Quick Sort in Java
    • Insertion Sort in Java
    • Sort String in Java
    • Program for Merge Sort in Java
  • Functions
    • String Functions in java
    • Math Functions in Java
    • Hashing Function in Java
    • Regular Expressions in Java
    • Recursion in Java
    • Java Callback Function
    • Java Call by Value
    • Java Call by Reference
    • HashMap in Java
    • Java String Concatenation
    • Java String Equals
    • Compare two Strings in Java
    • Virtual Function in Java
    • Java newInstance()
    • split() Function in Java
    • trim() Function in Java
    • Replace() Function in Java
    • substring() Function in Java
    • Strictfp in Java
    • String Reverse Function in Java
    • Java String getBytes
    • Java Replace Char in String
    • Shuffle() in Java
    • addAll() in Java
    • FileWriter in Java
    • Java Stream Filter
    • Java FileInputStream
    • replaceAll() in Java
    • repaint in Java
    • copy() in Java
    • Java max()
    • Java min()
    • Java Timestamp
    • Java URLConnection
    • Java StringJoiner
    • Java KeyStore
    • Java InetAddress
    • Java getMethod()
    • swap() in Java
    • Deadlock in Java
    • Range in Java
    • Java Repository
    • Java Dictionary
    • Calculator in Java
    • Mutable String in Java
    • Mutable vs Immutable Java
    • Native Methods in Java
    • StringBuffer Class in Java
    • String Class in Java
    • Java URL Class
    • Java Vector Class
  • Polymorphism
    • What is Polymorphism
    • Polymorphism in Java
    • Runtime Polymorphism in Java
    • Overloading and Overriding in Java
    • Overloading in Java
    • Method Overloading in Java
    • Function Overloading in Java
    • Overriding in Java
    • Method Overriding in Java
    • Final Keyword in Java
    • Super Keyword in Java
    • instanceOf in Java
    • Java Authenticator
    • Java Alias
  • Collections
    • What is TreeMap in Java?
    • Sorting in Collection
    • Java Collections Class
    • Hashtable in Java
    • Java EnumMap
    • Java LinkedHashMap
    • Reverse Linked List in Java
    • LinkedList in Java
  • Date Time
    • java.util.Date
    • Java Clock
    • Java Instant
    • Java LocalTime
    • Java ZoneId
    • Java ZoneOffset
    • Java varargs
    • Java LocalDate
    • Java OffsetDateTime
    • Java LocalDateTime
    • Java Duration
    • Java DayOfWeek
    • Java Period
    • Timer in Java
    • Java TimeZone
    • Java Date Picker
  • Advanced
    • Methods in Java
    • Serialization in Java
    • Inner Class in Java
    • Anonymous Inner Class in Java
    • Java Stack Methods
    • Java Static Nested Class
    • Synchronized Block in Java
    • Static Synchronization in Java
    • Abstract Class in Java
    • Access Modifiers in Java
    • Non Access Modifiers in Java
    • Bit Manipulation in Java
    • Encapsulation in Java
    • Singleton Class in Java
    • Wrapper Class in Java
    • Nested Class in Java
    • Java Matcher
    • Java Pattern Class
    • Java File Class
    • Final Class in Java
    • Stack Class in Java
    • Anonymous Class in Java
    • StringBuilder Class in Java
    • StringBuffer in Java
    • Java Directories
    • JSON in Java
    • Object Class in Java
    • What is Multithreading in java
    • Java Thread Priority
    • Daemon Thread in Java
    • Java Thread Pool
    • Java ThreadLocal
    • Association in Java
    • Queue in Java
    • Functional Programming in Java
    • ClassLoader in Java
    • Interface in Java
    • Functional Interface in Java
    • Java Queue Interface
    • Collection Interface in Java
    • Object Cloning in Java
    • Java.net URI
    • Java Assertion
    • Vector in Java
    • Applets in Java
    • Template in Java
    • Java Shutdown Hook
    • 2D Graphics in Java
    • Autoboxing and Unboxing in Java
    • Comparable in Java Example
    • Java Annotations
    • Java User Input
    • Serialization in Java
    • Dynamic Binding in Java
    • Java Parse String
    • Java Adapter Classes
    • Immutable Class in Java
    • String Initialization in Java
    • String Manipulation in Java
    • ThreadGroup in Java
    • Java Iterate Map
    • Java IO
    • Java?OutputStreamWriter
    • DataInputStream in Java
    • Java BufferedReader
    • Java BufferedWriter
    • Java BufferedInputStream
    • Java ByteArrayInputStream
    • Java ByteArrayOutputStream
    • Java RandomAcessFile
    • Java PrintStream
    • Java PrintWriter
    • Java URLEncoder
    • Java Scanner Class
    • Java Console
    • Java Runtime class
    • Java Base64
    • Java Base64 Encoding
    • Java Base64?Decode
    • Finalize in Java
    • Java Parallel Stream
    • Java Getter Setter
    • Set Interface in Java
    • How to Connect Database in Java
    • How to Create Webservice in Java
    • Composition in Java
    • BinarySearch() in Java
    • Exception Handling in Java
    • Java NullPointerException
    • Java NoSuchElementException
    • Java ConcurrentModificationException
    • Java ArithmeticException
    • Java IOException
    • Java RuntimeException
    • NumberFormatException in Java
    • Java ArrayIndexOutOfBoundsException
    • Java ClassNotFoundException
    • Java FileNotFoundException
    • Java InterruptedException
    • Finally in Java
    • Java Default Method
    • Java Locale
    • Tuples in Java
    • Java ServerSocket
    • Java Lambda Expressions
    • Java DatagramSocket
    • Java Animation
  • MISc
    • What is Synchronization in Java
    • What is Concurrency in Java
    • What is Design Pattern in Java
    • What is Generics in Java
    • What is API in Java
    • What is a Binary Tree in Java
    • What is Java Garbage Collector
    • What is Java Inheritance
    • Thread Life cycle in Java
    • Object Oriented Programming in Java
    • Java App Development
    • Java Naming Conventions
    • Java hashCode()
    • Java Transient
    • JSTL In Java
    • Comparable in Java 
    • Aggregation in Java
    • EJB in Java
    • @deprecated in Java
    • Java @Inherited
    • @SuppressWarnings in Java
    • Java @Override
  • Programs
    • Patterns in Java
    • Star Patterns in Java
    • Number Patterns in Java
    • Swapping in Java
    • Factorial in Java
    • Fibonacci Series in Java
    • Reverse Number in Java
    • Palindrome in Java
    • Armstrong Number in Java
    • Squares in Java
    • Square Root in Java
    • Special Number in Java
    • Anagram Program in Java
    • Strong Number in Java
    • Random Number Generator in Java
    • Matrix Multiplication in Java
    • Socket Programming in Java
    • Prime Numbers in Java
    • String Comparison in Java
    • Leap Year Program in Java
    • Reverse String in Java
    • Design Patterns in Java
    • Happy Numbers in Java

Related Courses

Java Course

JavaScript Certification Course

jQuery Training Course

Java Training Courses

Free Java Training Courses

JavaFX Training

Java Training Course

Footer
About Us
  • Blog
  • Who is EDUCBA?
  • Sign Up
  • Corporate Training
  • Certificate from Top Institutions
  • Contact Us
  • Verifiable Certificate
  • Reviews
  • Terms and Conditions
  • Privacy Policy
  •  
Apps
  • iPhone & iPad
  • Android
Resources
  • Free Courses
  • Java Tutorials
  • Python Tutorials
  • All Tutorials
Certification Courses
  • All Courses
  • Software Development Course - All in One Bundle
  • Become a Python Developer
  • Java Course
  • Become a Selenium Automation Tester
  • Become an IoT Developer
  • ASP.NET Course
  • VB.NET Course
  • PHP Course

© 2020 - EDUCBA. ALL RIGHTS RESERVED. THE CERTIFICATION NAMES ARE THE TRADEMARKS OF THEIR RESPECTIVE OWNERS.

EDUCBA Login

Forgot Password?

EDUCBA
Free Software Development Course

Web development, programming languages, Software testing & others

*Please provide your correct email id. Login details for this Free course will be emailed to you
Book Your One Instructor : One Learner Free Class

Let’s Get Started

This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to our Privacy Policy

EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you
EDUCBA
Free Software Development Course

Web development, programming languages, Software testing & others

*Please provide your correct email id. Login details for this Free course will be emailed to you

Special Offer - Java Training (40 Courses, 29 Projects, 4 Quizzes) Learn More