200+ Junior Software Engineer Interview Questions and Answers

An array is a data structure that stores a collection of elements of the same type. It allows for easy access and manipulation of data.

• Arrays are declared by specifying the data type of the elements and the size of the array.

• For example, to declare an array of strings in C++, you would write: string myArray[5];

• Arrays can be accessed using index values, starting from 0.

• Elements in an array can be modified or accessed using their respective index values.

An object is an instance of a class in object-oriented programming. It is a data structure that contains both data and methods.

• Objects are created by instantiating a class using the 'new' keyword.

• Objects have attributes (data) and methods (functions) associated with them.

• Example: Creating an object 'car' from a class 'Vehicle' - Vehicle car = new Vehicle();

Routing in ASP.NET MVC is used to map incoming browser requests to specific controller actions.

• Routing helps in defining URL patterns and mapping them to controller actions.

• It allows for creating clean and user-friendly URLs.

• Routing also enables parameter passing in URLs for dynamic content.

• Example: RouteConfig.cs file in ASP.NET MVC project defines the routing configuration.

Arrays are a collection of elements of the same data type, while ArrayList is a dynamic array that can grow or shrink in size.

• Arrays have a fixed size, while ArrayList can dynamically resize.

• Arrays can only store elements of the same data type, while ArrayList can store elements of different data types.

• Arrays are faster in terms of performance compared to ArrayList.

• Arrays are part of the core Java language, while ArrayList is a class in the Java Collections Framework.

Query to select employee with second highest salary

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT 1,1 to select the second highest salary

• Join with employee table to get employee details

Model is bound to controller in MVC through data binding techniques.

• Use data binding frameworks or libraries provided by the MVC framework.

• Define the model class and its properties in the controller.

• Map the model properties to the corresponding view elements.

• Update the model data in the controller based on user input or other events.

• Ensure proper synchronization between the model and the view.

A C program to swap alternative letters in a given string.

• Declare a character array to store the input string.

• Use a loop to iterate through the string and swap alternative letters.

• Print the modified string.

Code to find longest and smallest string from array of strings

• Iterate through the array and compare lengths to find longest and smallest strings

• Use built-in functions like length() to determine string lengths

• Consider edge cases like empty array or strings of equal length

The tags used to create a table in HTML are <table>, <tr>, <td>, and <th>.

• <table> tag is used to define the table itself

• <tr> tag is used to define a row within the table

• <td> tag is used to define a cell within a row

• <th> tag is used to define a header cell within a row

The new keyword is used in object-oriented programming to create a new instance of a class or struct.

• Used to allocate memory for a new object

• Invokes the constructor of the class or struct

• Returns a reference to the newly created object

Object-oriented programming concepts focus on data and methods, including inheritance, encapsulation, polymorphism, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the complex implementation details and showing only the necessary features.

Fibonacci series program using recursion

• Define a recursive function to calculate Fibonacci series

• Base case: return 0 if n is 0, return 1 if n is 1

• Recursive case: return sum of previous two Fibonacci numbers

Async and await are keywords in JavaScript used to work with asynchronous code, making it easier to write and understand.

• Async functions return a Promise, which allows the function to pause execution and wait for a Promise to resolve before continuing.

• Await can only be used inside an async function to pause execution until a Promise is settled.

• Async/await is syntactic sugar built on top of Promises, making asynchronous code easier to read and write.

• Example: async function fet...read more

Reversing a linked list involves changing the direction of pointers to go from the end to the beginning.

• Create three pointers: current, previous, and next.

• Iterate through the linked list, updating pointers to reverse the direction.

• Return the new head of the reversed linked list.

I am passionate about using data to solve complex problems and make informed decisions.

• Fascinated by the power of data in uncovering insights and patterns

• Enjoy working with statistics and machine learning algorithms

• Believe in the potential of data science to drive innovation and improve processes

Joins are used in databases to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column.

• 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 matc...read more

The super keyword is used in Java to refer to the immediate parent class object.

• Used to access methods and variables of the parent class

• Helps in achieving method overriding in inheritance

• Can be used to call the constructor of the parent class

• Example: super.methodName();

let, const, and var are used to declare variables in JavaScript. Closures are functions that have access to their outer scope even after the outer function has finished executing.

• let: block-scoped variable declaration, can be reassigned

• const: block-scoped variable declaration, cannot be reassigned, but its properties can be modified

• var: function-scoped variable declaration, can be reassigned

• Closure: inner function has access to outer function's variables even after outer func...read more

Angular is a popular front-end framework for building dynamic web applications.

• Angular is a JavaScript framework developed by Google.

• It allows developers to create single-page applications with a rich user interface.

• Angular uses TypeScript, a superset of JavaScript, for building applications.

• It provides features like data binding, dependency injection, and routing.

• Angular is widely used for building interactive web applications.

• Example: Creating a todo list application using ...read more

The author of Java is James Gosling.

• James Gosling is a Canadian computer scientist.

• He is known as the father of Java programming language.

• He developed Java while working at Sun Microsystems in the early 1990s.

Joins are used in SQL to combine data from two or more tables based on a related column.

• Joins are used to retrieve data from multiple tables in a single query

• There are different types of joins such as inner join, left join, right join, and full outer join

• Joins are based on a related column between the tables

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

Yes, I have experience with AI through coursework and personal projects.

• Studied AI algorithms and techniques in university courses

• Implemented machine learning models for personal projects

• Used AI libraries like TensorFlow and scikit-learn

I believe AI has the potential to revolutionize industries and improve efficiency, but ethical considerations must be taken into account.

• AI has the ability to automate tasks and processes, increasing efficiency and productivity.

• AI can analyze large amounts of data quickly and accurately, leading to valuable insights and predictions.

• Ethical considerations such as bias in AI algorithms and job displacement must be addressed to ensure responsible AI development.

• Examples of AI ap...read more

Design includes elements such as layout, color, typography, and functionality.

• Layout

• Color

• Typography

• Functionality

Abstract class can have both abstract and non-abstract methods, while functional interface can have only one abstract method.

• Abstract class can have constructors, fields, and methods, while functional interface can only have one abstract method.

• Abstract class can have abstract and non-abstract methods, while functional interface can only have one abstract method.

• Abstract class can provide default implementations for methods, while functional interface cannot.

• Example: Abstract...read more

Dynamic method dispatch is a mechanism by which a call to an overridden method is resolved at runtime rather than compile time.

• In dynamic method dispatch, the actual method called is determined by the type of object at runtime.

• It allows for polymorphism in object-oriented programming languages.

• Example: Animal class with a method 'makeSound', and subclasses Dog and Cat that override 'makeSound'. Calling 'makeSound' on an Animal reference will execute the appropriate method bas...read more

Microservices architecture is a way of designing software as a collection of small, independent services.

• Benefits include increased scalability, flexibility, and resilience

• Drawbacks include increased complexity and potential communication overhead

• Examples of companies using microservices include Netflix and Amazon

MQ's in AS400 are message queues used for inter-process communication.

• MQ's in AS400 allow different programs or processes to communicate with each other by sending and receiving messages.

• They provide a reliable and asynchronous way of exchanging data between applications.

• MQ's can be used for various purposes such as sending notifications, transferring data between systems, or triggering actions based on events.

• They are commonly used in enterprise applications for integrating ...read more

India needs investment in infrastructure, education, healthcare, and technology for development.

• Investment in infrastructure like roads, railways, and airports to improve connectivity

• Improvement in education system to provide quality education and skill development

• Enhancement of healthcare facilities and access to affordable healthcare services

• Promotion of technology innovation and digital literacy to drive economic growth

JobQ is a job queue in AS400 that manages the execution of batch jobs.

• JobQ is used to prioritize and schedule batch jobs on AS400.

• It allows multiple jobs to be submitted and executed in a specific order.

• Jobs in the queue can be held, released, or deleted as needed.

• JobQ provides a way to manage and control the execution of batch jobs efficiently.

• Example: WRKJOBQ command is used to display the jobs in a specific job queue.

Yes, I have knowledge of CSS and Bootstrap.

• I have experience in using CSS to style web pages.

• I am familiar with Bootstrap framework and its components.

• I have used Bootstrap to create responsive and mobile-friendly websites.

• I understand the importance of CSS and Bootstrap in web development.

Shallow copy creates a new object but references the same memory location, while deep copy creates a new object with new memory location.

• Shallow copy can be achieved using the copy() method or the copy module, while deep copy can be achieved using the deepcopy() method from the copy module.

• Shallow copy only copies the top-level object and references nested objects, while deep copy recursively copies all objects.

• Changes to nested objects in a shallow copy will reflect in the o...read more

Function to convert Roman numeral to integer

• Create a dictionary mapping Roman numerals to their integer values

• Iterate through the input Roman numeral string from right to left

• If current numeral value is less than the next numeral value, subtract it from the total

• Otherwise, add it to the total

• Return the total integer value

I worked on a web-based project management software for tracking tasks and deadlines.

• Developed front-end using React.js

• Implemented back-end using Node.js and MongoDB

• Integrated third-party APIs for additional functionality

Stream API in Java-8 is a powerful tool for processing collections of data.

• Stream API provides a functional approach to processing data.

• It allows for parallel processing of data.

• Stream API includes methods like filter, map, reduce, and collect.

• Example: List numbers = Arrays.asList(1, 2, 3, 4, 5); numbers.stream().filter(n -> n % 2 == 0).forEach(System.out::println);

• Example: List names = Arrays.asList("John", "Mary", "Bob"); String result = names.stream().map(String::toUpperCa...read more

Tableau is a powerful data visualization tool that helps in analyzing and presenting complex data in an easy-to-understand format.

• Allows creation of interactive dashboards and reports

• Enables quick and easy data exploration

• Provides real-time collaboration and sharing of insights

• Supports integration with various data sources

• Offers advanced analytics and predictive modeling capabilities

Statically typed variables are explicitly declared with a data type, while dynamically typed variables have their data type determined at runtime.

• Statically typed languages require variable types to be declared before use (e.g. Java, C++)

• Dynamically typed languages infer variable types at runtime (e.g. Python, JavaScript)

Event Loop in Node.js is a mechanism that allows Node.js to perform non-blocking I/O operations.

• Event Loop is responsible for handling asynchronous operations in Node.js.

• It allows Node.js to perform multiple operations concurrently without blocking the execution of other code.

• Event Loop continuously checks the event queue for any pending events and executes them in a loop.

• Example: When reading a file in Node.js, the Event Loop allows the program to continue executing other ta...read more

To reverse an array of numbers, iterate through the array and swap elements from start to end.

• Iterate through the array using two pointers, one starting from the beginning and the other from the end.

• Swap elements at the two pointers and move the pointers towards the center until they meet.

• Example: Input array [1, 2, 3, 4, 5], after reversing becomes [5, 4, 3, 2, 1].

Object oriented concepts are programming principles that revolve around objects and classes.

• Objects: Instances of classes that encapsulate data and behavior

• Classes: Blueprint for creating objects with attributes and methods

• Inheritance: Allows a class to inherit attributes and methods from another class

• Polymorphism: Ability for objects to take on different forms or behaviors

• Encapsulation: Bundling data and methods that operate on the data within a single unit

OOPs concepts include encapsulation, inheritance, polymorphism, and abstraction. Abstraction is a concept where only relevant information is shown to the user, while interface is a blueprint for classes.

• OOPs concepts: encapsulation, inheritance, polymorphism, abstraction

• Abstraction: showing only relevant information to the user

• Interface: blueprint for classes, defines methods without implementation

• Example: Abstraction - Car dashboard displaying speed without showing internal ...read more

Encapsulation is the process of hiding implementation details and providing access to only necessary information.

• Encapsulation is achieved through access modifiers like public, private, and protected.

• It helps in maintaining data integrity and security.

• Example: A class with private variables and public methods to access them.

• Encapsulation also enables abstraction, which allows for easier maintenance and modification of code.

Functions return a value while stored procedures do not.

• Functions are used to perform a specific task and return a value.

• Stored procedures are used to execute a set of SQL statements and do not return a value.

• Functions can be used in SQL statements while stored procedures cannot.

• Functions can be called from within stored procedures.

• Functions are deterministic while stored procedures may not be.

• Functions can be used in views while stored procedures cannot.

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

• OOPs focuses on creating objects that contain data and methods to manipulate that data.

• It allows for encapsulation, inheritance, and polymorphism.

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

• Inheritance allows a class to inherit properties and behavior from another class.

• Polymorphism allows objects of different classes to b...read more

Yes, I have experience with SQL.

• Proficient in writing complex SQL queries

• Experience with database design and normalization

• Familiar with stored procedures and triggers

An IP address is a unique identifier assigned to devices on a network. There are two types of IP addresses: IPv4 and IPv6.

• IP stands for Internet Protocol

• IPv4 addresses are 32-bit and represented in dotted decimal notation (e.g. 192.168.0.1)

• IPv6 addresses are 128-bit and represented in hexadecimal notation (e.g. 2001:0db8:85a3:0000:0000:8a2e:0370:7334)

• IP addresses are used to identify devices on a network and enable communication between them

Main concepts in Java include object-oriented programming, inheritance, polymorphism, encapsulation, and abstraction.

• Object-oriented programming: Java is an object-oriented language where everything is treated as an object.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Ability of an object to take on many forms.

• Encapsulation: Bundling of data and methods that operate on the data into a single unit.

• Abstraction: Hiding the implem...read more