Junior Software Engineer Trainee Interview Questions and Answers

Java is a popular programming language used for developing various applications.

• Class is a blueprint for creating objects, which are instances of classes.

• Abstraction is the concept of hiding implementation details and showing only necessary features.

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

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• Method overloading is having multiple methods in the...read more

I have a strong understanding of SQL queries and can write complex queries efficiently.

• Proficient in writing SQL queries to retrieve, update, and manipulate data

• Familiar with joins, subqueries, indexes, and stored procedures

• Experience optimizing queries for performance

• Knowledge of database normalization and data modeling

• Example: SELECT * FROM table WHERE condition;

Binary search has a time complexity of O(log n) where n is the number of elements in the array.

• Time complexity is O(log n) as it divides the array in half at each step

• Best case is O(1) when the element is found at the middle of the array

• Worst case is O(log n) when the element is not present in the array

Oops stands for Object-Oriented Programming. Inheritance is a mechanism in which a new class inherits properties and behaviors from an existing class.

• Oops stands for Object-Oriented Programming

• Inheritance allows a new class to inherit properties and behaviors from an existing class

• Inheritance promotes code reusability and helps in creating a hierarchical relationship between classes

A key is a unique identifier used to access or retrieve data in a data structure.

• A key is used in key-value pairs to uniquely identify the value associated with it.

• Keys are commonly used in dictionaries, hash tables, and databases.

• Examples of keys include employee IDs, product codes, and usernames.

Encapsulation in .NET is the concept of bundling data and methods that operate on the data into a single unit, known as a class.

• Encapsulation helps in hiding the internal state of an object and restricting access to it.

• It allows for better control over the data by preventing outside code from directly accessing or modifying it.

• Access to the data is provided through methods, which can enforce validation rules or perform additional logic.

• For example, a class representing a bank...read more

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

• Use JOIN keyword to combine tables based on a related column

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

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

Object-oriented programming (OOP) is a programming paradigm based on the concept of objects, which can contain data in the form of fields (attributes) and code in the form of procedures (methods).

• OOP focuses on creating reusable code by organizing data and behavior into objects.

• Key principles of OOP include encapsulation, inheritance, and polymorphism.

• Examples of OOP languages include Java, C++, and Python.