50+ Interview Questions and Answers

I have implemented various software applications on Linux OS.

• Developed a web application using Python Flask framework on Linux server

• Created a custom Linux kernel module for a hardware device driver

• Implemented a distributed system using Apache Kafka on Linux machines

• Optimized performance of a database server running on Linux by tuning kernel parameters

A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit.

• Microprocessors are used in various electronic devices such as computers, smartphones, and gaming consoles.

• Register names include program counter (PC), accumulator (ACC), general-purpose registers (GPR), and memory address register (MAR).

• Registers are used to store data and instructions temporarily for processing.

• The number of registers and thei...read more

C++ is an extension of C with object-oriented programming features.

• C++ supports object-oriented programming while C does not.

• C++ has classes and templates while C does not.

• C++ has better support for exception handling than C.

• C++ has a standard library while C does not.

• C++ allows function overloading while C does not.

Arrays are contiguous blocks of memory while linked lists are made up of nodes that point to the next node.

• Arrays have fixed size while linked lists can grow dynamically.

• Insertion and deletion are faster in linked lists than in arrays.

• Arrays have better cache locality while linked lists have better memory utilization.

• Arrays are accessed using indices while linked lists are accessed using pointers.

• Examples of arrays include int[] and char[] while examples of linked lists inclu...read more

The process of converting Example.c file to Example.exe involves several steps.

• Preprocessing: includes header file inclusion, macro expansion, and conditional compilation

• Compilation: converts source code to object code

• Linking: combines object code with libraries to create executable file

• Debugging: identifying and fixing errors in code

• Optimization: improving performance of executable file

Data abstraction is the process of hiding implementation details and showing only necessary information.

• Abstraction is achieved through abstract classes and interfaces.

• It helps in reducing complexity and increasing efficiency.

• Example: abstract class Shape with abstract method draw() implemented by its subclasses like Circle and Rectangle.

I am comfortable working with multiple languages and have experience in doing so.

• I have experience working with languages such as Java, Python, C++, and JavaScript.

• I am able to quickly adapt to new languages and learn them efficiently.

• I understand the importance of proper documentation and commenting in code to ensure readability for others.

• I have worked on projects that required integration of multiple languages, such as a web application with a backend in Python and a front...read more

SQL query to join two tables

• Use JOIN keyword to combine two tables based on a common column

• Specify the columns to be selected using SELECT keyword

• Use ON keyword to specify the common column between two tables

Recursion is a technique where a function calls itself to solve a problem. WAP for recursion is to write a program using recursion.

• Recursion is used to solve problems that can be broken down into smaller sub-problems.

• The base case is the condition where the function stops calling itself.

• The recursive case is where the function calls itself with a smaller input.

• Example: Factorial of a number can be calculated using recursion.

• Example: Fibonacci series can be generated using rec...read more

TCP/IP is a protocol used for communication between devices on the internet. OSI model is a conceptual framework for network communication.

• TCP/IP is a suite of protocols that governs communication between devices on the internet.

• OSI model is a conceptual framework that divides network communication into seven layers.

• TCP/IP is based on a four-layer model, which includes the application, transport, internet, and network access layers.

• The OSI model includes the physical, data li...read more

Program counter is a register that stores the memory address of the next instruction to be executed by the processor.

• Program counter is also known as instruction pointer.

• It is a part of the processor's control unit.

• The value of program counter is incremented after each instruction is executed.

• If a program counter is corrupted, the processor may execute incorrect instructions.

• Example: If the program counter is pointing to memory address 100, the next instruction to be executed...read more

To get unique elements from a list, use set() function.

• Convert the list to a set using set() function

• Convert the set back to list using list() function

• Example: list(set(['apple', 'banana', 'apple', 'orange'])) will return ['apple', 'banana', 'orange']

SQL commands are used to interact with databases and manipulate data.

• SELECT: retrieve data from a database

• INSERT: add new data to a database

• UPDATE: modify existing data in a database

• DELETE: remove data from a database

• CREATE: create a new database or table

• ALTER: modify the structure of a database or table

• DROP: delete a database or table

• JOIN: combine data from multiple tables

• GROUP BY: group data based on a specific column

• ORDER BY: sort data based on a specific column

Memory is allocated to objects dynamically during runtime based on their size and type.

• Memory allocation is done using the 'new' keyword in languages like Java and C++.

• In languages like Python, memory allocation is handled automatically by the interpreter.

• Memory allocation can also be done using functions like malloc() and calloc() in C.

• Memory is released using the 'delete' keyword in languages like Java and C++.

• Memory management is important to prevent memory leaks and optim...read more

A program to reverse a given string.

• Create an empty string to store the reversed string.

• Iterate through the original string from end to start.

• Append each character to the empty string.

• Return the reversed string.

Pointers are variables that store memory addresses. Heap is a region of memory used for dynamic memory allocation.

• Pointers are used to access memory directly

• Heap is used for dynamic memory allocation

• Pointers can be used to create data structures like linked lists

• Heap memory must be manually managed to avoid memory leaks

Join is a SQL operation that combines rows from two or more tables based on a related column between them.

• Join is used to retrieve data from multiple tables in a single query.

• There are four types of joins: Inner Join, Left Join, Right Join, and Full Outer Join.

• Inner Join returns only the matching rows from both tables.

• Left Join returns all the rows from the left table and matching rows from the right table.

• Right Join returns all the rows from the right table and matching rows...read more

Find the first non-repeating character in an array.

• Use a hash table to store the frequency of each character.

• Iterate through the array and check the frequency of each character.

• Return the first character with a frequency of 1.

Comparable is an interface used for natural ordering while Comparator is an interface used for custom ordering.

• Comparable is implemented by the class whose objects need to be sorted

• Comparator is implemented by a separate class to define custom sorting logic

• Comparable uses compareTo() method to compare objects

• Comparator uses compare() method to compare objects

• Example: String class implements Comparable interface for natural ordering

• Example: Employee class implements Comparator...read more

Hash table is a data structure that maps keys to values using a hash function.

• Hash function maps keys to indices in an array

• Collisions can occur, which can be resolved using techniques like chaining or open addressing

• Lookup, insertion, and deletion operations have an average time complexity of O(1)

Destructuring is a way to extract values from objects and arrays into distinct variables.

• Destructuring can be used with arrays and objects

• It allows you to extract values from nested objects and arrays

• You can also set default values for variables that may not exist in the object or array

• Example: const {name, age} = {name: 'John', age: 30};

• Example: const [first, second] = ['one', 'two'];

Object-oriented programming paradigm that focuses on objects and classes for code organization and reusability.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (object)

• Inheritance: Ability for a class to inherit properties and behavior from another class

• Polymorphism: Ability for objects of different classes to respond to the same method call in different ways