300+ Junior Software Engineer Interview Questions and Answers

Types of joins in SQL include inner join, outer join, left join, and right join.

• Inner join: returns rows when there is a match in both tables

• Outer join: returns all rows when there is a match in one of the 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

Polymorphism is the ability of an object to take on many forms. It allows objects of different classes to be treated as if they were of the same class.

• Polymorphism is achieved through method overriding and method overloading.

• Method overriding is when a subclass provides a specific implementation of a method that is already provided by its parent class.

• Method overloading is when a class has two or more methods with the same name but different parameters.

• Example: A shape class ...read more

Query for fetching the second highest salary from a table.

• Use ORDER BY and LIMIT to fetch the second highest salary.

• Exclude the highest salary using subquery or WHERE clause.

Yes, I am willing to work in C++, C# and WPF development.

• I have experience working with C++ and C# in previous projects.

• I am familiar with WPF development and have created user interfaces using WPF.

• I am eager to learn and expand my skills in C++, C# and WPF development.

To swap two numbers, store one number in a temporary variable, assign the value of the second number to the first, and then assign the value of the temporary variable to the second.

• Declare two variables to store the numbers

• Assign values to the variables

• Declare a third variable to store the temporary value

• Assign the value of the first variable to the third variable

• Assign the value of the second variable to the first variable

• Assign the value of the third variable to the second ...read more

To check source object in AS400, use the DSPOBJD command.

• Use the DSPOBJD command followed by the library name and object name to display object details.

• The source object type should be specified as *PGM or *FILE.

• The output will include information like source file, member, and source type.

Count the number of words in a user input string.

• Use the split() method to split the string into an array of words.

• Get the length of the array to get the number of words.

• Handle edge cases like leading/trailing spaces and multiple spaces between words.

Use Floyd's Cycle Detection Algorithm to detect two loops in a linked list.

• Initialize two pointers, slow and fast, both starting at the head of the linked list.

• Move slow pointer by one step and fast pointer by two steps in each iteration.

• If they meet at some point, there is a loop. Reset one pointer to head and move both by one step until they meet again to find the start of the loop.

Setting up a project in a live environment involves several key steps to ensure smooth deployment and operation.

• 1. Define project requirements: Gather all necessary specifications and features needed for the project.

• 2. Choose a hosting environment: Select a suitable server or cloud service (e.g., AWS, Azure) based on project needs.

• 3. Set up version control: Use Git to manage code changes and collaborate with team members.

• 4. Configure the environment: Set up necessary software...read more

Java code can create star patterns using loops, allowing for various designs with asterisks printed on multiple lines.

• Nested Loops: Use nested for-loops to control the number of rows and columns for the star pattern.

• Example 1: For a right-angled triangle pattern, use: for (int i = 1; i <= 5; i++) { for (int j = 1; j <= i; j++) { System.out.print('*'); } System.out.println(); }

• Example 2: For a pyramid pattern, use: for (int i = 1; i <= 5; i++) { for (int j = 5; j > i; j--) { S...read more

C# program to reverse a string and check if it is a palindrome.

• Declare a string variable and initialize it with the input string

• Convert the string to a character array

• Reverse the character array using Array.Reverse() method

• Convert the character array back to string

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

I developed a data pipeline using AWS services to process and analyze large datasets for real-time insights.

• Utilized AWS S3 for data storage, allowing for scalable and durable storage of raw data.

• Implemented AWS Lambda for serverless data processing, enabling real-time data transformation.

• Used AWS Glue for ETL (Extract, Transform, Load) processes to clean and prepare data for analysis.

• Leveraged Amazon Redshift for data warehousing, facilitating complex queries and analytics.

• E...read more

Methods in collections are used to manipulate and retrieve data from collections in programming.

• Some common methods include add(), remove(), contains(), size(), and clear().

• For example, the add() method is used to add an element to a collection, while remove() is used to remove an element.

• The contains() method is used to check if a collection contains a specific element, while size() returns the number of elements in the collection.

• Finally, the clear() method is used to remov...read more

Visualize data in Tableau using various charts and graphs.

• Select appropriate chart type based on data and analysis goal

• Use color, size, and shape to encode additional information

• Create interactive dashboards for exploration and analysis

• Utilize Tableau's built-in features such as filters and parameters

• Consider audience and design for effective communication

I am open to discussing the package and would like to know more about the benefits and growth opportunities.

• I am willing to negotiate based on the overall package, including benefits and growth opportunities.

• I would like to know more about the company culture and values.

• I am open to discussing the possibility of performance-based incentives.

• I am interested in opportunities for professional development and advancement.

• I would like to know more about the specific responsibiliti...read more

Program to append a string at the middle of another string

• Find the middle index of the original string

• Use string slicing to split the original string into two parts

• Concatenate the first part, new string, and second part to form the final string

Microservices are a software development technique where applications are composed of small, independent services that communicate with each other.

• Microservices break down applications into smaller, loosely coupled services

• Each service is responsible for a specific function and can be developed, deployed, and scaled independently

• Communication between services is typically done through APIs

• Examples include Netflix, Amazon, and Uber which use microservices architecture

Query to select sum of salaries department wise

• Use GROUP BY clause to group salaries by department

• Use SUM() function to calculate the sum of salaries

• Join the employee and department tables on department ID

I am comfortable with Java, Python, and JavaScript.

• Java

• Python

• JavaScript

Find 3 indices whose values sum up to 0.

• Use nested loops to compare each index with every other index.

• Store the sum of each pair of indices in a hash table.

• Check if any three indices have a sum of 0.

Call by value passes a copy of the variable's value, while call by reference passes a reference to the variable.

• Call by value passes the actual value of the variable being passed to a function.

• Call by reference passes a reference (memory address) of the variable being passed to a function.

• Changes made to the parameter in call by value do not affect the original variable, while changes in call by reference do.

Tableau was preferred due to its ease of use and better visualization capabilities.

• Tableau has a more user-friendly interface compared to Power BI.

• Tableau offers better visualization options and allows for more customization.

• Tableau has a larger community and more resources available for support.

• Power BI is more suitable for data modeling and analysis.

• The decision to use Tableau over Power BI was based on the specific needs of the project.

C++ is a compiled language with pointers and memory management, while Java is an interpreted language with garbage collection.

• C++ is faster and more memory-efficient than Java.

• Java is platform-independent, while C++ is not.

• C++ allows for manual memory management with pointers, while Java has automatic garbage collection.

• Java has a simpler syntax and is easier to learn than C++.

• C++ is commonly used for system-level programming, while Java is used for web and mobile application...read more

OOP is a programming paradigm based on objects that encapsulate data and behavior, promoting code reusability and modularity.

• Encapsulation: Bundling data and methods that operate on the data within one unit (e.g., a class).

• Inheritance: Mechanism to create a new class from an existing class, inheriting its properties (e.g., a 'Dog' class inheriting from an 'Animal' class).

• Polymorphism: Ability to present the same interface for different underlying forms (e.g., method overridin...read more

Polymorphism allows methods to do different things based on the object it is acting upon, enhancing flexibility in programming.

• Polymorphism is a core concept in Object-Oriented Programming (OOP).

• It allows methods to be defined in multiple forms.

• There are two types: compile-time (method overloading) and runtime (method overriding).

• Example of method overloading: A function 'add' can take two integers or two floats.

• Example of method overriding: A subclass can provide a specific ...read more

Informatica is a data integration tool used for ETL (Extract, Transform, Load) processes.

• Used for data integration and ETL processes

• Can connect to various data sources and targets

• Provides a graphical interface for designing and managing workflows

• Supports scheduling and monitoring of workflows

• Can handle large volumes of data

• Examples of use cases include data warehousing, data migration, and data synchronization

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.