300+ Junior Software Engineer Interview Questions and Answers

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.

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

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

Delegates are reference types that hold a reference to a method. They provide flexibility and extensibility in C#.

• Delegates allow methods to be passed as parameters to other methods.

• They can be used to implement callbacks and event handlers.

• Delegates can be chained together to create a pipeline of methods to be executed.

• They provide a way to decouple the caller from the implementation of a method.

• Delegates can be used to implement the observer pattern.

• Examples of delegates in...read more

Remove duplicates from an array of strings using various methods.

• Use a Set: Convert the array to a Set to automatically remove duplicates. Example: `const uniqueArray = [...new Set(array)];`

• Filter Method: Use `filter()` to keep only unique elements. Example: `const uniqueArray = array.filter((item, index) => array.indexOf(item) === index);`

• Reduce Method: Use `reduce()` to build a new array with unique values. Example: `const uniqueArray = array.reduce((acc, item) => acc.inclu...read more

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

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.

Exceptional handling is the process of identifying, catching, and responding to errors in software applications.

• Exception handling is used to prevent application crashes and provide a graceful way to handle errors.

• It involves using try-catch blocks to catch exceptions and handle them appropriately.

• Logging and reporting exceptions is also important for debugging and improving application performance.

• Best practices include using specific exception types, avoiding catching gener...read more

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

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

Python programming encompasses fundamental concepts like variables, data types, control structures, functions, and object-oriented programming.

• Variables: Used to store data. Example: `x = 5`.

• Data Types: Common types include integers, floats, strings, and lists. Example: `name = 'Alice'`.

• Control Structures: Includes if-else statements and loops. Example: `if x > 0: print('Positive')`.

• Functions: Blocks of reusable code. Example: `def greet(): print('Hello!')`.

• Object-Oriented Pr...read more

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

Python allows easy variable swapping using tuple unpacking, making code concise and readable.

• Tuple unpacking: a, b = b, a swaps values without a temporary variable.

• Readability: This method is clear and concise, improving code maintainability.

• Efficiency: Python's tuple unpacking is optimized for performance.

• Example: a, b = 5, 10; a, b = b, a results in a = 10, b = 5.

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

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();

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

MVC is a design pattern in .NET that separates application logic into Model, View, and Controller components.

• Model: Represents the data and business logic. Example: A class that interacts with a database.

• View: The user interface that displays data. Example: HTML pages in an ASP.NET application.

• Controller: Handles user input and updates the Model and View. Example: A controller action method that processes form submissions.

• Separation of concerns: MVC promotes organized code by...read more

Inheritance allows a class to inherit properties and methods from another class, promoting code reuse and organization.

• Inheritance enables a new class (child) to inherit attributes and methods from an existing class (parent).

• It promotes code reusability, allowing developers to create a new class with minimal code duplication.

• Example: If 'Animal' is a parent class, 'Dog' can be a child class that inherits properties like 'species' and methods like 'makeSound()'.

• Inheritance can...read more

A structured cabling system is a standardized approach to cabling that supports multiple hardware uses and is flexible for future needs.

• Consists of various components like cables, connectors, and patch panels.

• Follows standards such as TIA/EIA-568 for installation and performance.

• Includes horizontal cabling, backbone cabling, and work area components.

• Supports various applications like voice, data, and video transmission.

• Example: Cat 6 cables for high-speed internet connections...read more