T & H SOFTWARE Interview Questions and Answers

Abstraction is the concept of hiding complex implementation details and showing only the necessary features to the outside world.

• Abstraction allows us to focus on what an object does rather than how it does it

• Achieved through abstract classes and interfaces in object-oriented programming

• Example: A car dashboard abstracts the internal workings of the car and provides only essential information to the driver

Query to retrieve the 3rd highest salary from the employee table

• Use the ORDER BY clause to sort salaries in descending order

• Use the LIMIT clause to retrieve the 3rd highest salary

Traverse the linked list to find the 2nd last node and return its value.

• Traverse the linked list while keeping track of the current and previous nodes.

• Once at the end of the list, return the value of the previous node.

Use two variables to keep track of the smallest and second smallest numbers in the array.

• Iterate through the array and update the variables accordingly.

• Initialize the variables with the maximum possible integer value to start with.

• Example: array = [5, 2, 8, 1, 3], smallest = 1, secondSmallest = 2.

The get() method in HashMap retrieves the value associated with a specified key.

• get() method takes a key as input and returns the value associated with that key in the HashMap.

• Internally, get() uses the hash code of the key to find the corresponding bucket in the HashMap.

• If multiple keys have the same hash code, get() uses the equals() method to find the correct key-value pair.

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization helps in minimizing data redundancy by dividing the database into multiple tables and defining relationships between them.

• It ensures data integrity by avoiding update anomalies and inconsistencies.

• There are different normal forms such as 1NF, 2NF, 3NF, BCNF, and 4NF, each with specific rules to follow.

• For example, in 1NF, each column should contain atomi...read more

Constraints are limitations or restrictions placed on a system or process.

• Constraints define the boundaries within which a system must operate.

• They can include limitations on resources, time, or functionality.

• Examples of constraints in software engineering include memory limitations, processing speed, and input/output requirements.