1000+ Software Engineer Interview Questions and Answers for Freshers

There are numerous ways to use a box full of pencils depending on the context and purpose.

• Pencils can be used for writing, drawing, sketching, coloring, shading, and more.

• They can be used for artistic purposes, schoolwork, office work, or personal use.

• Pencils can also be used as a tool for measurement, as a makeshift stylus, or even as a musical instrument.

• The number of ways to use a box full of pencils is virtually limitless and depends on the creativity and imagination of t...read more

Difference between server.transfer and Response.redirect

• Server.Transfer transfers control to another page on the server without the client knowing

• Response.Redirect sends a message to the client to redirect to another page

• Server.Transfer is faster and more efficient than Response.Redirect

• Server.Transfer can only be used within the same application, while Response.Redirect can be used to redirect to any URL

Locks are synchronization mechanisms used to control access to shared resources in multi-threaded environments.

• Locks prevent multiple threads from accessing shared resources simultaneously.

• They ensure that only one thread can access a shared resource at a time.

• Locks help in preventing race conditions and maintaining data integrity.

• They can be implemented using various techniques such as mutexes, semaphores, or monitors.

• In a non pre-emptive uni processor system, where only one...read more

Virtual memory allows the operating system to use disk space as an extension of RAM when there is no swap space.

• Virtual memory allows programs to use more memory than physically available.

• It provides a way to manage memory efficiently by swapping data between RAM and disk.

• Without swap space, virtual memory cannot be used effectively.

• Virtual memory helps in running large programs and multitasking.

• It allows for memory protection and isolation between processes.

Identify the first repeating digit in a given string of digits.

• Iterate through the string and keep track of seen digits using a set.

• Return the first digit that repeats, or -1 if no digit repeats.

• Time complexity: O(n), where n is the length of the input string.

To scale up application, use load balancers and monitor logs to identify failures.

• Use load balancers to distribute traffic across multiple instances

• Monitor logs to identify where the failure occurred

• Implement fault tolerance and redundancy to prevent future failures

• Use auto-scaling to automatically add or remove instances based on traffic

• Real-world example: Amazon Web Services (AWS) uses load balancers and auto-scaling to handle millions of requests

• Code example: Use try-catch...read more

Hash table. No, it is not possible to create a data structure with all operations in O(1) time.

• Hash table uses a hash function to map keys to indices in an array.

• Insertion and deletion can be done in O(1) time on average.

• Search retrieval can also be done in O(1) time on average.

• However, worst-case scenarios can result in O(n) time complexity.

• It is not possible to create a data structure with all operations in O(1) time.

Find duplicates in an array of integers within a specified range.

• Iterate through the array and keep track of the count of each element using a hashmap.

• Identify elements with count greater than 1 as duplicates.

• Return the duplicate elements as the output.

• Handle edge cases like empty array or no duplicates found.

Finding smallest of 4 numbers without using >.< and min function in Java.

• Initialize a variable with the first number

• Compare it with the remaining numbers using if-else statements

• If a smaller number is found, update the variable

• Repeat until all numbers are compared

• The final value of the variable will be the smallest number

Ratio of ages of Raj and Sakshi is 8:7 and their sum is 60. Find their ratio after 6 years.

• Let the ages of Raj and Sakshi be 8x and 7x respectively

• Their sum is 60, so 15x = 60

• Hence, x = 4

• After 6 years, Raj's age will be 8x+6 and Sakshi's age will be 7x+6

• The ratio of their ages after 6 years will be (8x+6):(7x+6)

I am comfortable with multiple coding languages including Java, Python, and C++.

• Proficient in Java, Python, and C++

• Experience with web development languages such as HTML, CSS, and JavaScript

• Familiarity with scripting languages like Bash and PowerShell

• Comfortable with SQL and NoSQL databases

• Knowledge of machine learning libraries like TensorFlow and Keras

Check if a sorted array from 1 to n has a repeated number.

• Iterate through the array and check if the current element is equal to the next element.

• If yes, return true. If no, continue iterating.

• If the loop completes without finding a repeated element, return false.

OOPS is used for creating modular, reusable and maintainable code.

• Encapsulation: Hiding implementation details and exposing only necessary information.

• Inheritance: Reusing code and creating a hierarchy of classes.

• Polymorphism: Using a single interface to represent multiple types of objects.

• Abstraction: Simplifying complex systems by breaking them down into smaller, more manageable parts.

• Examples: Java, C++, Python, Ruby, etc.

Rearrange array in consecutive pair multiplication in descending order.

• Create a new array to store the multiplied values

• Use a loop to iterate through the original array and multiply consecutive pairs

• Write a compare function to sort the new array in descending order

Single linked list has one pointer while doubly linked list has two. Doubly linked list is preferred for easier traversal in both directions.

• Single linked list has only one pointer which points to the next node while doubly linked list has two pointers which point to the next and previous nodes.

• Doubly linked list allows for easier traversal in both directions, while single linked list only allows for traversal in one direction.

• Doubly linked list requires more memory due to th...read more

Interview questions for Software Engineer position covering DSA, project-based tech questions, OOPS, and puzzle.

• Be prepared to answer DSA questions such as finding the Nth Fibonacci number with memoization, finding duplicate nodes in a linked list, and binary tree DSA questions.

• Expect project-based tech questions that may require you to explain your approach to solving a particular problem.

• Brush up on OOPS concepts and be ready to apply them to real-world scenarios.

• Be prepare...read more

AI is a technology that enables machines to learn from experience and perform tasks that typically require human intelligence.

• AI is used in various industries such as healthcare, finance, and transportation

• AI can be used for natural language processing, image recognition, and predictive analytics

• Examples of AI include virtual assistants like Siri and Alexa, self-driving cars, and fraud detection systems

• AI has the potential to revolutionize industries and improve efficiency an...read more

Given an infinite staircase with a broken kth step, find the maximum height we can reach in n rounds of jumping i steps.

• We can start by jumping the maximum number of steps in each round until we reach the broken step.

• After reaching the broken step, we can discard the i steps that would land us on the broken step and jump the remaining steps.

• We can continue this pattern until we reach the maximum height we can reach without stepping on the broken step.

Area of square except inscribed circle

• Find area of square

• Subtract area of circle from square

• Area of square = L^2, Area of circle = pi*(L/2)^2

• Answer = L^2 - pi*(L/2)^2

Software testing is the process of evaluating a software item to detect differences between given input and expected output.

• Software testing ensures that the software is bug-free and meets the requirements

• It involves various types of testing such as functional, performance, security, etc.

• Testing can be done manually or through automation tools like Selenium, Appium, etc.

I would use a Linked List data structure for frequent insertion and deletion operations.

• Linked Lists have constant time complexity for insertion and deletion operations.

• Arrays have a linear time complexity for these operations.

• Doubly Linked Lists allow for efficient deletion of nodes.

• Examples of use cases include implementing a queue or stack.

Sorting algorithms are used to arrange data in a specific order. There are various types of sorting algorithms.

• Types of sorting algorithms include: bubble sort, selection sort, insertion sort, merge sort, quick sort, heap sort, counting sort, radix sort, and bucket sort.

• Bubble sort compares adjacent elements and swaps them if they are in the wrong order.

• Selection sort selects the smallest element and swaps it with the first element, then selects the second smallest and swaps ...read more

A linked list is a data structure that consists of a sequence of nodes, where each node contains a reference to the next node.

• Advantages of linked list:

• - Dynamic size: Linked lists can grow or shrink as needed.

• - Efficient insertion and deletion: Adding or removing elements from a linked list is faster than an array.

• - Flexibility: Linked lists can be easily modified and reorganized.

• Representation of a linked list:

• - Each node contains data and a reference to the next node.

• - The...read more

The boot up process of a typical machine involves several stages, including power-on, BIOS initialization, bootloader loading, kernel loading, and initialization of the operating system.

• The boot up process starts with the power-on of the machine.

• The BIOS (Basic Input/Output System) is initialized, which performs a series of hardware checks and initializes the system components.

• The bootloader is loaded, which is responsible for loading the operating system.

• The kernel of the op...read more

I need to improve my time management skills.

• Prioritize tasks based on urgency and importance

• Set realistic deadlines and stick to them

• Avoid multitasking and focus on one task at a time

• Use tools like calendars and to-do lists to stay organized

Code to delete a node from a singly linked list given the head and offset of the node.

• Traverse the linked list until the node at the given offset is reached.

• Update the next pointer of the previous node to skip the node to be deleted.

• Free the memory occupied by the node to be deleted.

To indicate error/failure in a function that returns a float, use a special value or an additional parameter.

• Use a special value like NaN or a negative value to indicate error/failure.

• Alternatively, add an additional parameter to the function to return an error code or message.

• Handle the error/failure condition appropriately in the calling code.

The number of ways to reach the nth step using 1 or 2 steps at a time.

• Use dynamic programming to solve this problem

• Create an array to store the number of ways to reach each step

• Initialize the first two elements of the array as 1, since there is only one way to reach the first and second steps

• For each subsequent step, the number of ways to reach it is the sum of the number of ways to reach the previous two steps

• Return the value at the nth index of the array

A binary search tree is a data structure where each node has at most two children, and the left child is smaller than the parent while the right child is larger.

• The maximum height of a binary search tree with n elements is n-1.

• The search complexity for the case when the height is maximum is O(n).

• To reduce the search complexity, we can balance the binary search tree using techniques like AVL trees or Red-Black trees.

Answers to common technical questions in a software engineering interview

• A transaction in DBMS is a sequence of operations that must be treated as a single unit of work. ACID properties ensure reliability and consistency of transactions.

• A thread is a lightweight process that shares memory and resources with other threads in the same process. A process is a separate instance of a program.

• Common Linux commands include ls, cd, mkdir, rm, and grep.

• sudo is used to run commands wit...read more

Public and private IP addresses are used in computer networks. Public IPs are globally unique and accessible from the internet, while private IPs are used within a local network.

• Public IP is assigned by the Internet Service Provider (ISP) and is used to identify a device on the internet.

• Private IP is assigned by a local network administrator and is used to identify a device within a local network.

• Public IPs are globally unique, allowing devices to communicate with each other ...read more

The query finds the employee name who earns the maximum salary.

• Use the SELECT statement to retrieve the employee name and salary from the database table.

• Use the ORDER BY clause to sort the results in descending order based on salary.

• Use the LIMIT clause to limit the result to only one row.

• Return the employee name from the query result.

Optimized approach to find third largest element from array using half traversal.

• Sort the array in descending order and return the element at index 2.

• Use a max heap to keep track of the top 3 elements while traversing the array.

• Use two variables to keep track of the second and third largest elements while traversing the array.

• Divide the array into two halves and find the maximum and second maximum in each half, then compare them to find the third largest element.

Two ways to write a sentence in mirror image form in Java: reverse string function and array conversion.

• Use the reverse() method of the String class to reverse the sentence

• Convert the sentence to a character array, then swap the first and last characters, second and second-to-last characters, and so on until the middle is reached

• Example: 'Hello World' becomes 'dlroW olleH'

To clear the 7th bit in a 32-bit register, perform a bitwise AND operation with a mask that has all bits set to 1 except the 7th bit.

• Create a mask with the 7th bit set to 0 and all other bits set to 1

• Perform a bitwise AND operation between the register and the mask

• Store the result back in the register