1. Reverse a String
  2. Check if a String is a Palindrome
  3. Remove Duplicates from a String
  4. Find the First Non-Repeating Character
  5. Count the Occurrences of Each Character
  6. Reverse Words in a Sentence
  7. Check if Two Strings are Anagrams
  8. Find the Longest Substring Without Repeating Characters
  9. Convert a String to an Integer
  10. Compress a String
  11. Find the Most Frequent Character
  12. Find All Substrings of a Given String
  13. Check if a String is a Rotation of Another String
  14. Remove All White Spaces from a String
  15. Check if a String is a Valid Shuffle of Two Strings
  16. Convert a String to Title Case
  17. Find the Longest Common Prefix
  18. Convert a String to a Character Array
  19. Replace Spaces with %20 (URL Encoding)
  20. Convert a Sentence into an Acronym
  21. Check if a String Contains Only Digits
  22. Find the Number of Words in a String
  23. Remove a Given Character from a String
  24. Find the Shortest Word in a String
  25. Find the Longest Palindromic Substring