
Practice 50 C# String Programming Questions
Q1. Write a C# program to reverse a string.
Input: String = "Hello"
Output: olleH
Q2. Write a C# program to count the number of vowels in a string.
Input: String = "Hello World"
Output: Vowels = 3
Q3. Write a C# program to find the length of a string.
Input: String = "Programming"
Output: Length = 11
Q4. Write a C# program to check if a string is a palindrome.
Input: String = "madam"
Output: Palindrome
Q5. Write a C# program to concatenate two strings.
Input: String1 = "Hello", String2 = "World"
Output: HelloWorld
Q6. Write a C# program to convert a string to uppercase.
Input: String = "hello"
Output: HELLO
Q7. Write a C# program to convert a string to lowercase.
Input: String = "HELLO"
Output: hello
Q8. Write a C# program to check if a string contains a specific character.
Input: String = "Hello", Character = 'e'
Output: Character found
Q9. Write a C# program to check if a string starts with a given substring.
Input: String = "Hello World", Substring = "Hello"
Output: Starts with Hello
Q10. Write a C# program to check if a string ends with a given substring.
Input: String = "Hello World", Substring = "World"
Output: Ends with World
Q11. Write a C# program to find the index of the first occurrence of a character in a string.
Input: String = "Hello", Character = 'l'
Output: Index = 2
Q12. Write a C# program to remove all spaces from a string.
Input: String = "Hello World"
Output: HelloWorld
Q13. Write a C# program to replace all occurrences of a character in a string.
Input: String = "Hello World", OldChar = 'o', NewChar = 'x'
Output: Hellx Wxrld
Q14. Write a C# program to split a string into an array of substrings.
Input: String = "apple,banana,orange", Separator = ','
Output: ["apple", "banana", "orange"]
Q15. Write a C# program to check if a string is empty.
Input: String = ""
Output: String is empty
Q16. Write a C# program to check if a string is null or empty.
Input: String = null
Output: String is null or empty
Q17. Write a C# program to compare two strings.
Input: String1 = "apple", String2 = "apple"
Output: Strings are equal
Q18. Write a C# program to find the first occurrence of a substring in a string.
Input: String = "Hello World", Substring = "World"
Output: Substring found at index 6
Q19. Write a C# program to convert the first letter of each word in a string to uppercase.
Input: String = "hello world"
Output: Hello World
Q20. Write a C# program to find the last occurrence of a character in a string.
Input: String = "Hello World", Character = 'o'
Output: Last occurrence at index 7
Q21. Write a C# program to check if a string contains only digits.
Input: String = "123456"
Output: Contains only digits
Q22. Write a C# program to check if a string contains only alphabetic characters.
Input: String = "Hello"
Output: Contains only alphabetic characters
Q23. Write a C# program to extract a substring from a string.
Input: String = "Hello World", StartIndex = 6, Length = 5
Output: World
Q24. Write a C# program to remove a specific character from a string.
Input: String = "Hello World", Character = 'o'
Output: Hell Wrld
Q25. Write a C# program to check if two strings are anagrams.
Input: String1 = "listen", String2 = "silent"
Output: Strings are anagrams
Q26. Write a C# program to trim leading and trailing whitespaces from a string.
Input: String = " Hello World "
Output: Hello World
Q27. Write a C# program to convert a string to a character array.
Input: String = "Hello"
Output: ['H', 'e', 'l', 'l', 'o']
Q28. Write a C# program to check if a string is a valid email address.
Input: String = "example@mail.com"
Output: Valid email address
Q29. Write a C# program to find the number of words in a string.
Input: String = "Hello World"
Output: Word count = 2
Q30. Write a C# program to reverse the words in a string.
Input: String = "Hello World"
Output: World Hello
Q31. Write a C# program to find the ASCII value of a character.
Input: Character = 'A'
Output: ASCII value = 65
Q32. Write a C# program to count the occurrence of a word in a string.
Input: String = "apple banana apple", Word = "apple"
Output: Occurrences = 2
Q33. Write a C# program to remove all occurrences of a word in a string.
Input: String = "apple banana apple", Word = "apple"
Output: banana
Q34. Write a C# program to join an array of strings into a single string.
Input: Array = ["apple", "banana", "cherry"]
Output: apple banana cherry
Q35. Write a C# program to replace a word in a string with another word.
Input: String = "Hello World", OldWord = "World", NewWord = "C#"
Output: Hello C#
Q36. Write a C# program to remove all vowels from a string.
Input: String = "Hello World"
Output: Hll Wrld
Q37. Write a C# program to check if a string is a valid URL.
Input: String = "http://example.com"
Output: Valid URL
Q38. Write a C# program to check if a string contains a given substring.
Input: String = "Hello World", Substring = "World"
Output: Contains substring
Q39. Write a C# program to convert a string to a number.
Input: String = "123"
Output: Number = 123
Q40. Write a C# program to format a string using placeholders.
Input: Name = "John", Age = 30
Output: Hello John, you are 30 years old
Q41. Write a C# program to remove duplicate characters from a string.
Input: String = "aabcc"
Output: abc
Q42. Write a C# program to find the longest word in a string.
Input: String = "The quick brown fox jumps over the lazy dog"
Output: Longest word = jumps
Q43. Write a C# program to convert a string to Title Case.
Input: String = "the quick brown fox"
Output: The Quick Brown Fox
Q44. Write a C# program to split a string into an array of words.
Input: String = "Hello World"
Output: ["Hello", "World"]
Q45. Write a C# program to replace a substring in a string using Regex.
Input: String = "The cat in the hat", OldWord = "cat", NewWord = "dog"
Output: The dog in the hat
Q46. Write a C# program to find the index of a substring in a string.
Input: String = "Hello World", Substring = "World"
Output: Index = 6
Q47. Write a C# program to check if a string contains digits.
Input: String = "abc123"
Output: Contains digits
Q48. Write a C# program to remove all punctuation marks from a string.
Input: String = "Hello, World!"
Output: Hello World
Q49. Write a C# program to convert a string to a boolean value.
Input: String = "true"
Output: Boolean = True
Q50. Write a C# program to generate a random string of a given length.
Input: Length = 5
Output: Random String = "abc12"