100+ Interview Questions and Answers

Explanation of final, finally and finalize in Java with examples

• final is a keyword used to declare a constant value or to prevent method overriding or class inheritance

• finally is a block of code that executes after try-catch block, regardless of exception occurrence

• finalize is a method that gets called by garbage collector before destroying an object

• final is used for declaring constant values, method parameters, and local variables

• String class is final in Java, which means it...read more

Regular expression for 10-digit numeric characters starting with 1, 2, or 3.

• Use the pattern ^[1-3]\d{9}$ to match the criteria

• The ^ symbol denotes the start of the string

• The [1-3] specifies that the first digit must be 1, 2, or 3

• \d{9} matches exactly 9 numeric digits

• $ indicates the end of the string

The different layers of Springboot application, webservers that come with Springboot, default webserver, changing default webserver, and configuring port on spring-boot.

• The different layers of Springboot application are presentation layer, service layer, business layer, and data access layer.

• The webservers that come with Springboot are Tomcat, Jetty, and Undertow.

• The default webserver is Tomcat.

• To change the default webserver, exclude the default starter and add the desired s...read more

A join in SQL is used to combine rows from two or more tables based on a related column between them.

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table.

• FULL JOIN returns rows when there is a match in one of t...read more

Java has four types of references: strong, weak, soft, and phantom.

• Strong references are the default and are used to refer to objects that are still in use.

• Weak references are used to refer to objects that can be garbage collected when there are no strong references to them.

• Soft references are used to refer to objects that should be garbage collected only when memory is low.

• Phantom references are used to track when an object is about to be garbage collected.

• References are use...read more

Rollout is a project to implement a solution in multiple locations, while implementation is a project to implement a solution in a single location.

• Rollout involves implementing a solution in multiple locations, while implementation is focused on a single location.

• Rollout projects are typically larger in scope and require more resources than implementation projects.

• Rollout projects may require customization for each location, while implementation projects may be more standardi...read more

Kafka is a distributed streaming platform that allows publishing and subscribing to streams of records.

• Kafka works by having producers publish messages to topics, which are then stored in partitions on brokers.

• Consumers subscribe to topics and read messages from partitions.

• To debug if messages are not received, use the command-line tool kafka-console-consumer to check if messages are being produced and consumed.

• Also check the Kafka logs for any errors or issues with the broke...read more

OOPS stands for Object-Oriented Programming System. It is a programming paradigm based on the concept of objects.

• OOPS focuses on creating objects that contain data in the form of fields (attributes) and code in the form of procedures (methods).

• Encapsulation, inheritance, and polymorphism are key principles of OOPS.

• Encapsulation refers to the bundling of data and methods that operate on the data into a single unit (object).

• Inheritance allows a class to inherit properties and b...read more

Answering questions related to Kubernetes deployment file, image pulling, and QoS for pods.

• Fields in deployment file: apiVersion, kind, metadata, spec (replicas, selector, template)

• Ways of pulling images: using imagePullPolicy (Always, IfNotPresent, Never), specifying image name and tag

• QoS for pods: Guaranteed (requests and limits specified), Burstable (only requests specified), BestEffort (no requests or limits specified)

WFH allows employees to work remotely from their homes, while WFO requires employees to work from a physical office location.

• WFH provides flexibility in work location and schedule, while WFO requires employees to be present in the office during specified hours.

• WFH may lead to increased productivity and work-life balance for some employees, while WFO allows for better collaboration and communication among team members.

• Examples: WFH - working from home on a laptop; WFO - workin...read more

WBS is a hierarchical breakdown of project deliverables. RBS is a hierarchical breakdown of project resources. RAD is a software development model.

• WBS stands for Work Breakdown Structure and is used to break down project deliverables into smaller, more manageable components.

• RBS stands for Resource Breakdown Structure and is used to break down project resources into smaller, more manageable components.

• RAD stands for Rapid Application Development and is a software development m...read more

Yes, reflection is a feature in Java that allows inspecting and modifying runtime behavior of a program.

• Reflection allows accessing and modifying fields, methods, and constructors of a class at runtime.

• It is useful for creating generic code, debugging, and testing.

• Example: getting the class name of an object using getClass() method.

• Example: accessing private fields of a class using reflection.

• Example: creating an instance of a class using reflection.

Inner classes are used for encapsulation and code organization. Static inner classes are used for utility classes.

• Inner classes are used to group related classes together and improve encapsulation.

• Non-static inner classes have access to the outer class's fields and methods.

• Static inner classes are used for utility classes that don't need access to the outer class's fields and methods.

• Inner classes can also be used for anonymous classes and event listeners.

Automation testing is the use of tools and scripts to execute test cases, while manual testing is performed manually by human testers.

• Automation testing involves the use of automation tools and scripts to execute test cases.

• Manual testing is performed manually by human testers without the use of automation tools.

• Automation testing is faster and more efficient for repetitive tasks.

• Manual testing allows for exploratory testing and human intuition.

• Automation testing is suitable ...read more

Inversion of Control is a design pattern where control is inverted from the application to a framework.

• In Springboot, a bean is created by annotating a class with @Component or its specialized annotations like @Service, @Repository, etc.

• Beans are injected using @Autowired annotation or constructor injection.

• Bean resolution is done by the Spring container which maintains a registry of all beans and their dependencies.

• Inversion of Control helps in decoupling the application cod...read more

Data management process involves understanding workflow, required approvals, and tasks before completing XYZ task.

• Understand the data management process and workflow for completing XYZ task

• Identify the necessary approvals required before completing the task

• Ensure proper documentation and record-keeping throughout the process

• Collaborate with relevant stakeholders to streamline the workflow

• Regularly review and update the data management process for efficiency

• Example: Before com...read more

StatefulSets are used for stateful applications that require stable network identities and persistent storage.

• StatefulSets are used for applications that require ordered deployment, scaling, and termination.

• They provide stable network identities and persistent storage for each pod in the set.

• Storage mapping is done using PersistentVolumeClaims (PVCs) which are bound to PersistentVolumes (PVs).

• Each pod in the StatefulSet gets a unique hostname based on its ordinal index, which...read more

Basic SQL skills include querying databases, manipulating data, and understanding database structures.

• Writing basic SQL queries to retrieve data from databases

• Understanding and using SQL functions and operators

• Creating and modifying database tables and relationships

• Using SQL to filter, sort, and group data

• Understanding basic SQL syntax and commands

The technology used was artificial intelligence in healthcare.

• AI algorithms for medical image analysis

• Machine learning for predicting patient outcomes

• Natural language processing for analyzing medical records

Yes

• A future method can be called from a batch class

• Future methods are used to perform long-running operations asynchronously

• Batch classes are used to process large data sets in smaller chunks

• Calling a future method from a batch class allows for parallel processing

Using Java 8 streams, search for a given string in a list of Strings.

• Create a stream from the list of Strings

• Use the filter() method to filter out the Strings that do not contain the given string

• Collect the filtered Strings into a new list using the collect() method

Java does not use pointers because it was designed to be a simpler and safer language, with automatic memory management.

• Java was designed to be a simpler and safer language compared to C/C++.

• Java uses references instead of pointers to access objects in memory.

• Pointers in C/C++ can lead to memory leaks and security vulnerabilities.

• Example: In C/C++, you can directly manipulate memory addresses using pointers, while in Java, you cannot.

1) do while loop executes the code block at least once before checking the condition, while loop checks the condition before executing the code block. 2) Call by reference passes the address of the variable, call by value passes the value of the variable. 3) Pointer is a variable that stores the memory address of another variable. 4) Array is a data structure that stores a collection of elements of the same data type. 5) C is a procedural programming language, C++ is an objec...read more

ISO 9001:2015 emphasizes risk-based thinking and a process approach to quality management.

• ISO 9001:2015 has a new high-level structure (HLS) that aligns with other ISO management system standards

• ISO 9001:2015 emphasizes leadership and engagement of people

• ISO 9001:2015 requires a documented information management system instead of a quality manual

• ISO 9001:2015 introduces the concept of risk-based thinking throughout the standard

• ISO 9001:2015 requires organizations to identify ...read more

Recruitment cycle involves sourcing, screening, interviewing, selecting, and onboarding. Job portals like Indeed, LinkedIn, and Glassdoor are commonly used.

• Recruitment cycle includes sourcing candidates, screening resumes, conducting interviews, selecting candidates, and onboarding.

• Popular job portals include Indeed, LinkedIn, Glassdoor, Monster, and CareerBuilder.

• To use job portals effectively, create a detailed profile, set up job alerts, customize job searches, and network...read more

ASAP methodology is a framework for SAP implementation that follows a structured approach.

• ASAP stands for Accelerated SAP.

• It is a phased approach that covers all aspects of implementation from project preparation to post-implementation support.

• It emphasizes on business process re-engineering and continuous improvement.

• It provides templates, tools, and guidelines for each phase of the project.

• It helps to reduce implementation time and cost while ensuring quality and customer s...read more

Linux is an open-source operating system based on Unix. Commands can be added using the terminal or by installing packages.

• Linux is free and can be customized to suit specific needs

• Commands can be added using the terminal by creating a script or alias

• Packages can be installed using package managers like apt-get or yum

• Examples of commands include ls, cd, mkdir, rm, etc.

Agile methodology is an iterative approach to project management that emphasizes flexibility and customer satisfaction.

• Agile focuses on delivering working software in short iterations

• It values collaboration between cross-functional teams and customers

• It emphasizes responding to change over following a plan

• Examples of Agile methodologies include Scrum, Kanban, and Extreme Programming (XP)

I have experience in configuring SAP MM, integrating with other modules, and working on SAP implementation projects.

• Configured organization structure in SAP MM to align with client's business requirements

• Assigned organization structure to various entities such as plants, storage locations, and purchasing organizations

• Integrated SAP MM with other modules like SAP SD for seamless order-to-cash process

• Worked on SAP implementation projects by conducting workshops, gathering requi...read more

Planning infocubes are used for planning and forecasting data, while remote infocubes are used for accessing data from a remote system.

• Planning infocubes are used for budgeting, forecasting, and planning data.

• Remote infocubes are used for accessing data from a remote system, such as a different SAP system.

• Remote infocubes can be used for reporting on data from multiple systems.

• Planning infocubes can be used for creating scenarios and simulations.

• Both types of infocubes are us...read more

Yes, we can call a future method from another future method.

• A future method can call another future method using the @future annotation.

• The second future method will be queued and executed after the first future method completes.

• It is important to note that there is a limit of 50 future method calls per Apex invocation.

A controller class in Springboot is used to handle REST API requests and responses.

• Annotate the class with @RestController

• Define methods for each API endpoint with @RequestMapping annotation

• Use appropriate HTTP methods like GET, POST, PUT, DELETE

• Inject dependencies using @Autowired annotation

• Return response using ResponseEntity class

Load factor for HASH MAP is the ratio of number of elements to the size of the table.

• Load factor determines the efficiency of the HASH MAP.

• It is calculated as the number of elements divided by the size of the table.

• A higher load factor means more collisions and slower performance.

• A good load factor is around 0.75.

• Load factor can be adjusted by increasing or decreasing the size of the table.

SQL is a language used to manage and query databases, PL/SQL is an extension that adds procedural programming capabilities.

• SQL is used for querying and manipulating data in databases.

• PL/SQL is a procedural language extension for SQL, allowing for more complex logic and programming capabilities.

• Data structures in SQL refer to the way data is organized and stored in tables.

• PL/SQL allows for the creation of custom data structures using variables, arrays, and records.

• Differences ...read more

A certificate authority issues a certificate by verifying the identity of the requester and digitally signing the certificate.

• Verify the identity of the requester through various methods such as domain validation, organization validation, or extended validation.

• Generate a public and private key pair for the requester.

• Create a certificate signing request (CSR) containing the requester's public key and identity information.

• Verify the information in the CSR and validate the requ...read more

To convert hours into seconds, multiply the number of hours by 3600.

• Multiply the number of hours by 3600 to get the equivalent seconds.

• For example, 2 hours = 2 * 3600 = 7200 seconds.

The .NET framework is a software development platform developed by Microsoft. OOPs stands for Object-Oriented Programming, a programming paradigm based on the concept of objects.

• The .NET framework is used for building various types of applications, including web, desktop, and mobile applications.

• OOPs is a programming paradigm that uses objects and classes to design and develop applications.

• In OOPs, objects are instances of classes that encapsulate data and behavior.

• Some key p...read more

args and kwargs are used to pass variable-length arguments to a function, but args is for positional arguments and kwargs is for keyword arguments.

• args is a tuple of positional arguments, while kwargs is a dictionary of keyword arguments

• args is used when the number of arguments is not known beforehand, while kwargs is used when passing named arguments

• Example: def my_func(*args, **kwargs):

• Example: my_func(1, 2, 3, name='John', age=30)

I have used a variety of programming languages including Java, Python, C++, and JavaScript.

• Java

• Python

• C++

• JavaScript

SQL is a language used for managing and querying databases, while PL/SQL is an extension of SQL used for procedural programming.

• SQL stands for Structured Query Language and is used for managing and querying relational databases.

• PL/SQL stands for Procedural Language/SQL and is an extension of SQL that adds procedural programming capabilities.

• SQL is used to retrieve and manipulate data in databases using queries like SELECT, INSERT, UPDATE, DELETE.

• PL/SQL allows for the creation...read more

An array is a data structure that stores a collection of elements of the same type. A string is a sequence of characters. Swapping numbers involves exchanging the values of two variables. A palindrome number reads the same forwards and backwards.

• An array can store multiple values of the same data type, accessed by index.

• A string is a sequence of characters enclosed in quotes, like 'hello'.

• Swapping numbers involves using a temporary variable to exchange their values.

• A palindro...read more

ConcurrentModificationException occurs when a collection is modified while iterating over it.

• Use Iterator to iterate over the collection instead of foreach loop.

• If modification is necessary, use Iterator's remove() method instead of collection's remove() method.

• Consider using synchronized collections or ConcurrentHashMap to avoid ConcurrentModificationException.

LDAP can be used to manage user accounts by storing user information in a centralized directory.

• Set up LDAP server and configure it to store user account information

• Use LDAP client tools to manage user accounts such as creating, modifying, or deleting accounts

• Authenticate users against LDAP server for access control

• Implement LDAP schema to define attributes and object classes for user accounts

Green Belt and Black Belt are both Six Sigma certifications, but Black Belt is a higher level of expertise.

• Green Belt is an entry-level certification in Six Sigma methodology

• Black Belt is a more advanced certification, requiring more training and experience

• Black Belts are typically responsible for leading Six Sigma projects and mentoring Green Belts

• Green Belts work on Six Sigma projects under the guidance of Black Belts

• Black Belts have a deeper understanding of statistical an...read more

In Java, exceptions can be handled using try-catch blocks to catch and handle specific exceptions.

• Use try-catch blocks to catch exceptions and handle them gracefully

• Use multiple catch blocks to handle different types of exceptions

• Use finally block to execute code regardless of whether an exception is thrown or not

• Throw custom exceptions using throw keyword

Yes, I have managed financials in my previous roles as a Project Manager.

• I have experience in creating and managing project budgets.

• I have worked closely with finance teams to track and monitor project expenses.

• I have prepared financial reports and presented them to stakeholders.

• I have implemented cost-saving measures and identified areas for financial improvement.

• I have ensured projects stay within budget and made adjustments as needed.

Implementing an iterator for a custom object

• Create a custom class and implement the Iterable interface

• Override the iterator() method to return a custom Iterator object

• Implement the hasNext() and next() methods in the Iterator class

• Use the for-each loop to iterate through the custom object

To troubleshoot network issues, start by checking physical connections, verifying network settings, testing connectivity, and analyzing network traffic.

• Check physical connections (cables, ports, etc.)

• Verify network settings (IP address, subnet mask, gateway, DNS)

• Test connectivity using tools like ping, traceroute, and netcat

• Analyze network traffic with tools like Wireshark or tcpdump

Network routing and switching knowledge up to CCNP level.

• Understanding of routing protocols such as OSPF, BGP, EIGRP

• Knowledge of VLANs, STP, VTP, and other switching technologies

• Ability to troubleshoot network connectivity issues

• Experience with Cisco IOS and Nexus operating systems

• Familiarity with network security concepts such as ACLs and firewalls

map transforms each element in a stream, while flatMap transforms each element into multiple elements

• map applies a function to each element in a stream and returns a new stream of the results

• flatMap applies a function that returns a stream for each element in the original stream, then flattens the streams into a single stream

• Example: map - stream.map(x -> x * x), flatMap - stream.flatMap(str -> Arrays.stream(str.split("")))

Forms are used to input data while reports are used to display data.

• Forms are used to collect and input data into a system.

• Reports are used to display and present data in a structured format.

• Forms are interactive and allow users to input data, while reports are static and provide information based on the data entered.

• Examples: A registration form on a website vs. a sales report generated from a database.

Lean Six Sigma is a methodology that combines Lean Manufacturing and Six Sigma to eliminate waste and improve quality.

• It focuses on reducing waste and increasing efficiency

• It uses statistical analysis to identify and solve problems

• It involves a structured approach to problem-solving

• It aims to improve customer satisfaction and reduce costs

• Example: A hospital uses Lean Six Sigma to reduce patient wait times and improve the quality of care

Spring MVC is a framework for building web applications in Java, following the Model-View-Controller design pattern.

• Spring MVC follows the Model-View-Controller design pattern, where the model represents the data, the view represents the UI, and the controller handles the user input.

• It provides components like DispatcherServlet, Controller, Model, and ViewResolver to handle requests and responses.

• It supports the use of annotations like @Controller, @RequestMapping, and @Model...read more

Java Collections framework is a set of classes and interfaces that provide various data structures and algorithms to store and manipulate collections of objects.

• Provides interfaces (List, Set, Map) and classes (ArrayList, HashSet, HashMap) for storing and manipulating collections of objects

• Includes utility classes like Collections for sorting, searching, and other operations on collections

• Supports generics to ensure type safety and reduce the need for explicit type casting

• Off...read more