61 Interview Coding Questions for Practice and Master Programming

You can not master any of the programming languages without Practice. The common thing that I see among all the expert programmers- they do Practice. Lots of Practice. Practice solving interview coding questions.

The more you practice the better you become in programming.

Programming is a skill best acquired by Practice and Example rather than from Books.

– Alan Turing

For every beginner, it is easy to start reading programming books and gaining theoretical knowledge. But what’s the next?

No one has become a programmer by reading books. You should actually do the programming.

Before going to list out interview coding questions for practice, let me tell you, these are the generic coding questions. You can use these coding questions to challenge yourself and to practice any programming language like Python, C/C++, Java, and all other generic computer languages.

How to Improve Coding Skills?

If you want to improve your coding skills, there is only one way- practice solving coding questions.

If you watch my video where I talked about the 5 things to improve your coding skills, practicing is the first and at the top.

Don’t forget to

What are the Advantages of Practicing Programming over Reading Programming Books?

Doing programming teaches you many things…

• Problem Solving Mindset
  How are programmers different from others? Because programmers think differently. The real programmer has the best problem-solving mindset. And to make that problem-solving mindset, you need to practice hard.
• Building Logic
  It makes you think. You see the problem, think about it and you build your logic.
• Improving Coding Ability
  Programming is not about memorizing all the programming syntax. It varies from the programming language. It is ok if you forget, you can always Google it. Programming helps you to build your logic. It teaches you – how you can improve your logic or your coding ability.
• Thinking Efficiently
  There can be multiple solutions to a single problem. Practicing programming is also about trying different solutions and choosing the most efficient one.
• Preparing for Placement
  I have curated this list of programming questions for your practice and it will also help you to prepare for coding rounds of any company. Many of the below programming questions have been asked in many placement interview rounds for IT jobs.
• Grasping over different Programming topics
  I have tried out to add the coding questions from each topic.
• Understanding Data Structure Real-Time
  You will never understand the essence and real purpose of data structure reading from the books. Practicing coding questions help you to understand data structure in real-time.

Call-of-Action to Improve Coding Skills

So, if you are serious about programming and want to be a unicorn programmer, here is the call of action for you.

• Choose the best programming language for you whether you choose high-paying programming languages or the easiest programming language if you are a beginner.
• Make a directory in your workspace.
• Install the best Text Editor based on your Operating System for writing code.
• Take the one problem given below.
• Think about the solution and logic to solve the problem.
• Write a program for it.
• Repeat for all other programming questions.

The More You Practice, The Better You Become.

So let’s dive right into our list…

List of Interview Coding Questions

Here I’m listing basic programming questions you should practice to master any of the programming languages.

We also have a list of coding questions categorized by the data structure.

Basic Coding Questions

1. Writing the “Hello, World!” program. (C/C++, Python, Java)
2. Write a program to display the list of even numbers.
3. Find the Factorial of a given number.
4. Compare Two Numbers using the else-if statement and output smaller and larger numbers.
5. Write a program to determine If the given year is a Leap year.
6. Print all the elements in the Fibonacci number series.
   Hint: This program can be implemented using a loop or recursion technique.
7. Write a program to check if the number is a Palindrome number or not.
8. Generate all the prime numbers between one & the given number.
9. Print the Pyramid of Stars using nested for loops.
10. Print Reversed pyramid on programming console using for loops & decrement operator.
11. Write a program for Nested Switch.
12. Write a program to calculate Circle Area using the radius.
13. Find the Factorial of a number using the recursion technique.
14. Print the Pyramid of numbers using for loops.
15. Write a program to Find a Maximum of Two Numbers using the conditional operator.
16. Write a program to Find a Minimum of Two Numbers using the conditional operator.
17. Write a program that will read a float type value from the keyboard and print the following output.
    1) the smallest integer which is not less than the number
    2) given the number
    3) the largest integer which is not greater than the number
18. Find the second largest/smallest element in the array list.
19. Choose a random number from the array. (Python)
20. Check if all the elements in the array are the same. (Python)
21. Print all the unique numbers from the array. (Python)
22. Write a program to generate 5 Random nos. between 1 to 100 and the number should not contain a decimal value.
23. Write a program to display a  grade according to Marks obtained by the student.
24. Find the SUM AND PRODUCT of a given Digit in the number.
25. Write a program to find the sum of all integers greater than 150 and less than 290 that are divisible by 3.
26. Write a program to concatenate strings using a for-loop.
27. Display the multiplication table for the given number.
28. Write a program to Swap the values given by the user without using the third variable. (Python)
29. Write a program to convert given the number of days into months and days. (For the sake of simplicity, assume that each month contains 30 days).
30. Print the Invert Triangle using the while loop.
31. Write a program to find whether a given number is Armstrong or not.
32. How to check if the given number is the power of 3 (k- any integer)?
33. Write a program to print the day of the week based on the given number using the switch case. (For example, print “Monday” for user input 1, print “Tuesday” for user input 2…)
34. What is the Harmonic Series? Write a program to generate the Harmonic Series.
35. Write a program to find the average of consecutive n-odd numbers and n-even numbers.
36. Print the Triangle as follow, using for loops. 1 2 3 4 5 6 7 8 9 10 … N
37. Create the class having a member variable of employee detail and getter and setter function for each variable.
38. Write a program to find the sum of diagonal elements in the matrix in Python.
39. Write the program to read and write a file. (Python, C/C++)
40. Find the longest line from the file. (Python)
41. Take the students Mark as User input and check the range of Mark. (Java)

String Handling

42. Find the first duplicate/repeated character in the string. (Python)
43. Write a program to check if the substring is present in the given string. (C/C++)
44. Write a program to reverse the given string. (Python)
45. How to reverse a string without affecting special characters?
46. How to convert the given string to an integer value? (C/C++)
47. Write a program to check the Palindrome String. (C/C++)
48. Write a program to check the Anagram String. (C/C++, Python)
49. Remove white spaces from the given string. (C/C++)
50. Find all the permutations of the given string. (Python)
51. Find Remainder without using Modulus Operator
52. Remove all the duplicate characters from the string

Sorting Algorithm

53. Write a program to check if the array is sorted. (C/C++)
54. Selection Sort (Python, C/C++)
55. Insertion Sort (Python)
56. Bubble Sort (C/C++)
57. QuickSort (Example | Algorithm | Programming | Complexity)

Bit Manipulation

58. Count the number of ones in the binary string. (C/C++)
59. How to Find 2’s Complement?
60. Write a program to convert the Decimal number to Binary. (C/C++)

If you are learning Python, check the bitwise operators in Python.

Advanced Coding Questions

61. Write a C program to upload the file to another PC connected to the network.
62. Write a C program to download the file from the network.

These two questions are more related to network programming. If the job profile is related to networking, you have to prepare for such questions. These questions were asked in the Persistent coding interview as per the experience shared by the candidate.

Dictionary (Only for Python)

62. How to convert a nested dictionary into a flattened dictionary in Python?

Make a Routine and Stick with It

Tips to make the best use of these Interview Coding Questions:

• If you want to master any programming language, move to a Linux system for coding practice.
• I have mentioned the list of programs you should practice. We are writing a solution for each of the programs listed here. I keep updating this space. You can bookmark this page for anytime reference.
• I need your help. You can also write the program for any of the programming questions. Submit your program or even you can send an email to [email protected] (don’t forget to add the description to the program you are sharing). I will publish your article on our portal. Along with your practice, you are helping other programmers.
• Make a schedule and challenge yourself to solve n coding questions every day.

Programming Tutorials for Reference

If you want to learn the fundamentals of any of the programming languages, do refer following links for the particular programming tutorial.

• Python
• C and C++
• Java

Interview and Placement Preparation References

If you are looking for a job in the IT sector or preparing for interviews, find the following resources useful.

• Placement Interview Questions Company Wise
• 7 Most Common HR Interview Questions
• 7 Steps of Effective Job Search Techniques  [Guidelines with Checklist]

If you face any challenges to write a program for any of the mentioned interview coding questions, feel free to discuss them in the comment section. It is all about, how you make the best use of all the resources you have on your plate.

If you put a gun to my head, I will try to remember more coding questions and will add them to this list for you. 😉 

Stay Tuned and Keep Practicing!

Aniruddha Chaudhari

I am a Python enthusiast who loves Linux and Vim. I hold a Master of Computer Science degree from NIT Trichy and have 10 years of experience in the IT industry, focusing on the Software Development Lifecycle from Requirements Gathering, Design, Development to Deployment. I have worked at IBM, Ericsson, and NetApp, and I share my knowledge on CSEstack.org.