200+ Developer Interview Questions and Answers

Using Spark, find categories of blood donors required.

• Load blood donor data into Spark

• Group donors by blood type

• Identify categories based on demand

• Output as array of strings

React is called unidirectional because data flows in one direction, from parent to child components.

• React's unidirectional data flow means that data is passed down from parent components to child components, but not the other way around.

• While callbacks can be used to send data back to parents from child components, this does not change the overall unidirectional flow of data in React.

• This one-way data flow helps to maintain a clear and predictable data flow in React applicati...read more

OOPs stands for Object-Oriented Programming while POPs stands for Procedure-Oriented Programming. Encapsulation is the concept of bundling data and methods that operate on the data into a single unit. Polymorphism refers to the ability of a single function or method to operate on different types of data.

• OOPs focuses on objects and classes, allowing for better organization and reusability of code.

• POPs focuses on procedures and functions, which can lead to less organized and le...read more

A two-way switch is a device that can be used to control a single electrical circuit from two different locations.

• A two-way switch typically has three terminals: a common terminal and two traveler terminals.

• The common terminal is connected to the power source, while the traveler terminals are connected to the load.

• The switch can be toggled between the two traveler terminals to control the circuit from different locations.

The CSS box model is a design concept that describes how elements are displayed on a web page.

• It consists of content, padding, border, and margin.

• The content is the actual element and its size is determined by width and height properties.

• Padding is the space between the content and the border.

• Border is the line that surrounds the content and padding.

• Margin is the space between the border and the next element.

• The box model can be adjusted using CSS properties like box-sizing a...read more

M scripting is a programming language used for data manipulation and analysis. Based workspace is a feature in M scripting for managing data and variables.

• M scripting is a programming language used in Power Query for data transformation and manipulation.

• Based workspace in M scripting allows users to manage data and variables in a structured manner.

• Examples of M scripting functions include Table.AddColumn, Table.TransformColumns, and List.Transform.

Props and cons are not specific terms in JavaScript. Did you mean pros and cons?

• Pros: flexibility, easy to learn, wide range of applications

• Cons: can be slow, can be difficult to debug, can have security vulnerabilities

Composition is a strong relationship where the child object cannot exist without the parent object. Aggregation is a weak relationship where the child object can exist independently.

• Composition is a 'has-a' relationship, where the parent object owns the child object.

• Aggregation is a 'has-a' relationship, where the child object is a part of the parent object.

• In composition, the child object's lifetime is managed by the parent object.

• In aggregation, the child object's lifetime ...read more

Program to find the smallest number from 5 given numbers.

• Declare an array of 5 integers.

• Take input of 5 numbers from user and store them in the array.

• Initialize a variable with the first element of the array.

• Loop through the array and compare each element with the variable.

• If the element is smaller than the variable, update the variable.

• After the loop, the variable will contain the smallest number.

• Print the smallest number.

Closures are functions that have access to variables in their outer scope, even after the outer function has returned.

• Closures are created when a function is defined inside another function.

• The inner function has access to the outer function's variables, even after the outer function has returned.

• Closures can be used to create private variables and methods in JavaScript.

• Example: function outer() { var x = 10; function inner() { console.log(x); } return inner; } var closure = ...read more

The interview question involves coding questions related to counting words in a sentence, determining if a linked list is circular, and creating a star pattern.

• To count the number of words in a sentence, split the sentence by spaces and count the number of resulting elements.

• To determine if a linked list is circular, use two pointers moving at different speeds - if they meet, the list is circular.

• To create a star pattern, use nested loops to print the desired pattern of stars...read more

React is a JavaScript library for building user interfaces, known for its component-based architecture and virtual DOM.

• React uses a virtual DOM for better performance by only updating the necessary parts of the actual DOM.

• React follows a component-based architecture, making it easier to reuse code and maintain.

• React allows developers to write JSX, a syntax extension that resembles HTML, to define the UI components.

• React is more focused on the view layer of the application, wh...read more

Join queries are used to combine data from multiple tables based on a common column.

• Join queries are used when data is spread across multiple tables and needs to be combined for analysis.

• They are useful for retrieving data from related tables, such as customer orders and order details.

• Join queries can be used to filter data based on specific criteria, such as only retrieving orders from a certain date range.

• There are different types of join queries, such as inner join, left j...read more

HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• HashMap is implemented using an array of linked lists or a balanced tree.

• It allows null values and at most one null key.

• The put() method is used to insert a key-value pair into the HashMap.

• The get() method is used to retrieve the value associated with a given key.

• Example: HashMap map = new HashMap<>();

Code to transpose a matrix

• Iterate through rows and columns of the matrix

• Swap the elements at (i,j) and (j,i) positions

• Return the transposed matrix

Program to reverse a string without using inbuilt function

• Create an empty string to store the reversed string

• Iterate through the original string from end to start and append each character to the new string

• Return the reversed string

The 4 pillars of C++ are Abstraction, Encapsulation, Inheritance, and Polymorphism.

• Abstraction: Hiding implementation details and showing only necessary information.

• Encapsulation: Binding data and functions together to prevent external interference.

• Inheritance: Creating new classes from existing ones, inheriting their properties and methods.

• Polymorphism: Using a single interface to represent multiple types of objects.

There are four types of joining in SQL: Inner Join, Left Join, Right Join, and Full Join.

• Inner Join returns only the matching rows from both tables.

• Left Join returns all the rows from the left table and matching rows from the right table.

• Right Join returns all the rows from the right table and matching rows from the left table.

• Full Join returns all the rows from both tables, with NULL values in the columns where there is no match.

• Examples: Inner Join - SELECT * FROM table1 IN...read more

Hooks are functions that allow you to use state and other React features without writing a class.

• Hooks were introduced in React 16.8

• They allow you to reuse stateful logic

• useState is a hook that allows you to add state to a functional component

• useEffect is a hook that allows you to perform side effects in a functional component

• useContext is a hook that allows you to consume a context in a functional component

My aim is to continuously improve my skills and knowledge in software development while contributing to the success of the company.

• To become a proficient developer

• To learn new technologies and programming languages

• To contribute to the success of the company

• To work collaboratively with other developers

• To deliver high-quality software products

Yes, integration between SAP DataSphere and SAC is possible.

• SAP DataSphere can be integrated with SAP Analytics Cloud (SAC) to enable data sharing and analysis.

• Integration allows users to access and analyze data from SAP DataSphere within SAC.

• Data can be imported from SAP DataSphere into SAC for further analysis and visualization.

• Integration enables real-time data updates and synchronization between SAP DataSphere and SAC.

• Users can create dashboards, reports, and visualizatio...read more

ABAP Dictionary is a central repository for data definitions used in SAP applications. ALV report events are user actions in ALV grid. OOPs ABAP is object-oriented programming in ABAP.

• ABAP Dictionary is used to define and manage data definitions in SAP applications

• ALV report events include user actions like clicking on a row or column header

• OOPs ABAP allows for object-oriented programming concepts like classes and inheritance

RPG3 and RPG4 are different versions of the RPG programming language. RPG3 is an older version, while RPG4 is a newer and more advanced version.

• RPG3 is the third version of the RPG programming language, while RPG4 is the fourth version.

• RPG4 introduced many new features and enhancements compared to RPG3.

• RPG4 supports free-format coding, which allows for more flexibility and readability in code.

• RPG4 has improved support for SQL integration, making it easier to work with databas...read more

Stages are the different phases of a process in nProcess Studio, a software development tool for creating business applications.

• nProcess Studio is a software development tool used for creating business applications

• Stages are the different phases of a process in nProcess Studio

• Each stage represents a step in the process and can have its own set of rules and actions

• Examples of stages include 'Data Entry', 'Validation', and 'Approval'

• Stages can be customized to fit the specific ...read more

A query string is a part of a URL that contains data to be passed to a web server.

• It starts with a question mark (?) and is followed by key-value pairs separated by ampersands (&).

• It is commonly used to filter or sort data on a web page.

• Example: www.example.com/search?q=apple&category=fruit

• To use it, simply append the query string to the end of the URL.

Development engineers play a crucial role in designing, testing, and implementing new products and technologies.

• Designing and developing new products and technologies

• Testing and evaluating prototypes to ensure they meet quality standards

• Collaborating with cross-functional teams to ensure successful product launch

• Identifying and resolving technical issues that arise during development process

• Staying up-to-date with industry trends and advancements in technology

• Creating and mai...read more

Debugging a website involves identifying and fixing errors in the code and design.

• Use browser developer tools to inspect elements and console logs

• Check for syntax errors and broken links

• Test website on different browsers and devices

• Use debugging tools like Xdebug or Firebug

• Ask for help from colleagues or online communities

The maximum runs that can be achieved in 5 overs depend on various factors such as the skill level of the batsmen and the pitch conditions.

• The maximum runs that can be scored in 5 overs is 150 if all the balls are hit for sixes.

• The average score in T20 cricket is around 150-170 runs in 20 overs, so in 5 overs, it would be around 40-50 runs.

• The runs scored also depend on the skill level of the batsmen, the pitch conditions, and the quality of the opposition bowlers.

• In a high-s...read more

Python is a high-level programming language known for its simplicity and readability.

• Python is an interpreted language, which means it does not need to be compiled before running.

• It has a large standard library that provides many useful modules and functions.

• Python supports multiple programming paradigms, including procedural, object-oriented, and functional programming.

• It is widely used in web development, data analysis, artificial intelligence, and scientific computing.

• Pyth...read more

RAP has revolutionized SAP applications by enabling developers to easily create and customize business applications.

• RAP (ABAP RESTful Application Programming Model) allows developers to quickly build responsive and flexible applications.

• It simplifies the development process by providing a consistent programming model and predefined templates.

• RAP enables developers to easily create OData services for SAP applications, making it easier to integrate with other systems.

• It allows ...read more

Multithreading in Java allows multiple threads to execute concurrently within a single program.

• Multithreading improves performance by allowing tasks to run in parallel.

• Each thread has its own stack and program counter, but share the same memory space.

• Java provides built-in support for multithreading through the java.lang.Thread class.

• Example: Creating a new thread by extending the Thread class or implementing the Runnable interface.

Future methods are asynchronous and execute in a separate thread, while Queueable allows chaining of jobs and can handle larger data volumes.

• Future methods are limited to 50 per transaction and cannot be chained

• Queueable can be chained and can handle up to 50 jobs in a single transaction

• Future methods are executed in a separate thread and are useful for long-running operations

• Queueable jobs can be scheduled to run at a specific time

• Both can be used to offload processing from ...read more

I know various Linux commands including ls, cd, mkdir, rm, cp, mv, grep, awk, sed, and more.

• ls - list directory contents

• cd - change directory

• mkdir - make directories

• rm - remove files or directories

• cp - copy files or directories

• mv - move or rename files or directories

• grep - search for a pattern in a file

• awk - manipulate text files

• sed - stream editor for filtering and transforming text

response.redirect is a method used in web development to redirect the user to a different URL.

• response.redirect is used to redirect the user to a different URL

• It is commonly used in web applications to redirect users after a successful login or when accessing restricted pages

• The method can be used with different programming languages and frameworks, such as ASP.NET, PHP, and Node.js

• The redirected URL can be specified as an absolute or relative path

Yes, I am comfortable with hybrid culture.

• I have experience working with teams from diverse cultural backgrounds.

• I am open-minded and adaptable to different work styles and communication methods.

• I believe that a hybrid culture can bring new perspectives and ideas to a team.

• I am willing to learn and embrace new cultural practices and customs.

Node.js is a backend runtime environment that allows developers to run JavaScript on the server side.

• Node.js is built on Chrome's V8 JavaScript engine.

• It is non-blocking and event-driven, making it efficient for handling multiple connections.

• Node.js is commonly used for building APIs, web servers, and real-time applications.

• It has a large ecosystem of libraries and frameworks, such as Express.js and Socket.io.

A standard sales process is a systematic approach used by sales teams to convert leads into customers.

• Identifying potential leads

• Qualifying leads to determine if they are a good fit for the product or service

• Presenting the product or service to the qualified leads

• Handling objections and negotiating terms

• Closing the sale

• Following up with customers for repeat business or referrals

DCA analysis in reservoir refers to Decline Curve Analysis, a method used to estimate future production rates of oil and gas wells.

• DCA is a common technique in reservoir engineering to forecast production decline over time.

• It involves fitting a decline curve to historical production data to predict future performance.

• Different decline curve models like exponential, hyperbolic, and harmonic are used depending on the reservoir characteristics.

• DCA helps in making informed decisi...read more

Development is the process of creating software applications or systems.

• It involves designing, coding, testing, and deploying software.

• Developers use programming languages and tools to create software.

• Development can be done for various platforms such as web, mobile, desktop, etc.

• It requires problem-solving skills and attention to detail.

• Examples of development include creating a website, building a mobile app, or designing a database system.

Sharing rules can be given to users by defining criteria-based sharing rules in Salesforce.

• Create sharing rules based on criteria like record ownership, role hierarchy, or sharing rules

• Define the access level (read-only or read/write) for the shared records

• Test the sharing rules to ensure they are working as expected

Hard links and soft links are two types of links used in Unix-like operating systems to create shortcuts to files.

• Hard links are direct pointers to the inode of a file, while soft links are indirect pointers to the file name.

• Hard links cannot link directories or files on different filesystems, while soft links can.

• If the original file is deleted, hard links still point to the data, while soft links become broken.

• Example: 'ln file1 file2' creates a hard link, 'ln -s file1 file...read more

Inheritance is a mechanism in object-oriented programming where a new class is created by inheriting properties of an existing class.

• Inheritance allows code reusability and saves time and effort in programming.

• The existing class is called the parent or base class, and the new class is called the child or derived class.

• The child class inherits all the properties and methods of the parent class and can also add its own unique properties and methods.

• For example, a class 'Animal'...read more

Reverse a string and check if it is a palindrome

• Reverse the string using built-in functions or manually

• Compare the reversed string with the original string to check if it is a palindrome

• Ignore spaces and punctuation when checking for palindrome

JIT compilation stands for Just-In-Time compilation, a technique used by some programming languages to improve performance.

• JIT compilation compiles code at runtime instead of ahead of time

• It can improve performance by optimizing code based on runtime information

• JIT compilation is used in languages like Java, .NET, and JavaScript

• Examples of JIT compilers include HotSpot for Java and V8 for JavaScript

Subjects in observable are streams of data that emit values over time.

• Subjects are both an observer and an observable

• They can multicast data to multiple subscribers

• They can emit new values using next() method

• Example: BehaviorSubject, ReplaySubject, AsyncSubject

OOPs stands for Object-Oriented Programming. Inheritance is a feature of OOPs where a class can inherit properties and behaviors from another class.

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

• Inheritance allows a class to inherit attributes and methods from another class.

• It promotes code reusability and helps in creating a hierarchical structure of classes.

• Example: Class 'Car' can inherit properties like 'color' and methods like 'drive' from class ...read more

Var is statically typed while dynamic is dynamically typed.

• Var is used to declare variables with a specific type at compile time.

• Dynamic is used to declare variables whose type is determined at runtime.

• Var is faster than dynamic because it doesn't require type checking at runtime.

• Dynamic is more flexible than var because it allows for late binding and duck typing.

• Example: var x = 5; dynamic y = "hello";