Hi Reader,

Hope you’re doing well!

So far, we’ve covered Numbers, Loops, and Arrays in previous articles.

Now it’s time to move to one of the most important topics for QA automation interviews - Strings.

In real projects, you constantly work with text data:

• Usernames and passwords
• API responses
• Error messages
• Validation messages
• Logs

That’s why strong string-handling skills are essential for any QA engineer who wants to move into automation.

Below are 12 string coding problems arranged from simple to slightly challenging. Try solving them in order.

String Coding Problems for Beginner QA Engineers

Prerequisite: loops and basic array knowledge

1. Print each character of a given string
2. Count the number of characters in a string (without using built-in length method)
3. Count the number of words in a sentence
4. Remove all white spaces from a string
5. Count how many times a particular character appears in a string
6. Reverse a given string
7. Count the number of vowels and consonants in a string
8. Convert lowercase letters to uppercase (without using built-in methods)
9. Check whether a string is a palindrome
10. Extract only digits from a string (example: "Test123QA45" → 12345)
11. Check whether two strings are anagrams
12. Find the first non-repeating character in a string

These problems help you practice:

• Loop usage
• Handling character comparisons
• Applying conditional logic on text
• Explaining your approach clearly during interviews

Now let’s talk honestly about something important.

You can absolutely use Google, YouTube, ChatGPT, or Gemini to check solutions.

That’s how modern learning works.

But don’t just copy and paste code.

Try solving each problem for at least 20–30 minutes on your own.

If you get stuck, then check for hints.

After seeing the solution, close it and write the program again yourself.

In interviews, they won’t ask if you’ve seen the problem before.

They will ask you to explain your logic.

Sometimes they will modify the question slightly.

Your thinking process matters more than memorized code.

Once you complete these problems:

• Push your solutions to GitHub
• Share a LinkedIn post about completing the String coding challenge
• Tag me - I’d love to see your progress

Next, we’ll move to Collections, which is another important area for QA automation interviews.

See you in the next email!

- Swaroop Nadella | LinkedIn​

P.S. I’ll continue sharing practical, beginner-friendly articles that genuinely help you grow as a QA engineer.

No spam - only useful content. You can read my previous email articles published here.