10+ VVF Interview Questions and Answers

Java doesn't support multiple inheritance to avoid the diamond problem and maintain simplicity.

• Java supports single inheritance to avoid ambiguity in method resolution.

• Multiple inheritance can lead to the diamond problem where a class inherits from two classes that have a common ancestor.

• Java uses interfaces to achieve multiple inheritance of type, allowing classes to implement multiple interfaces.

Sort a string array in alphabetical order

• Use a sorting algorithm like quicksort or mergesort

• Remember to compare strings using strcmp() function

• Handle uppercase and lowercase letters properly

Abstract class is a class that cannot be instantiated and is used as a blueprint for other classes to inherit from.

• Cannot be instantiated directly

• Can have abstract methods that must be implemented by subclasses

• Can have non-abstract methods as well

SQL and Python are fundamental skills for a software engineer.

• SQL is used for managing relational databases and querying data.

• Python is a popular programming language for data analysis, web development, and automation.

• Python can be used to interact with SQL databases using libraries like SQLAlchemy and psycopg2.

• Understanding SQL and Python can help with tasks like data manipulation, reporting, and automation.

• Examples of SQL commands include SELECT, INSERT, UPDATE, and DELETE....read more

OOPS concepts refer to Object-Oriented Programming concepts like Inheritance, Polymorphism, Encapsulation, and Abstraction.

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

• Polymorphism: Ability for objects of different classes to respond to the same method.

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

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

Given an array of n-1 numbers 1<=a[i]<=n, find the missing number.

• Calculate the sum of all numbers from 1 to n using the formula n*(n+1)/2

• Calculate the sum of all elements in the array

• Subtract the sum of array elements from the sum of all numbers to get the missing number

UML diagrams are visual representations of software systems. Sequence and class diagrams depict system structure and behavior, while activity diagrams show system processes.

• UML diagrams are used to model software systems and their components

• Sequence diagrams show the interactions between objects in a system

• Class diagrams depict the structure of a system and its classes

• Activity diagrams show the flow of activities and processes in a system

• UML diagrams are commonly used in soft...read more

Scope of tuning in a SQL query can be found by analyzing query performance, identifying bottlenecks, and optimizing indexes.

• Analyze query performance using tools like SQL Profiler or Execution Plan

• Identify bottlenecks such as slow queries, high CPU usage, or long execution times

• Optimize indexes by adding, removing, or modifying indexes to improve query performance

Insert is used to add a single row into a table, while insert all is used to add multiple rows into a table in a single statement.

• Insert is used to add a single row into a table.

• Insert all is used to add multiple rows into a table in a single statement.

• Insert all is more efficient than using multiple insert statements.