Practice 100 C# Basic Programming Questions

Practice 100 C# Basic Programming Questions

Q1. Write a C# program to add two numbers.  
  Input: 5, 10  
  Output: 15

Q2. Write a C# program to subtract two numbers.  
  Input: 20, 8  
  Output: 12

Q3. Write a C# program to multiply two numbers.  
  Input: 4, 6  
  Output: 24

Q4. Write a C# program to divide two numbers.  
  Input: 25, 5  
  Output: 5

Q5. Write a C# program to find the remainder of two numbers.  
  Input: 15, 4  
  Output: 3

Q6. Write a C# program to swap two numbers using a temporary variable.  
  Input: x = 10, y = 20  
  Output: x = 20, y = 10

Q7. Write a C# program to swap two numbers without using a temporary variable.  
  Input: a = 15, b = 25  
  Output: a = 25, b = 15

Q8. Write a C# program to check if a number is even or odd.  
  Input: 7  
  Output: Odd

Q9. Write a C# program to check if a number is positive, negative, or zero.  
  Input: -5  
  Output: Negative

Q10. Write a C# program to find the largest of three numbers.  
   Input: 3, 7, 5  
   Output: 7

Q11. Write a C# program to calculate the factorial of a number.  
   Input: 5  
   Output: 120

Q12. Write a C# program to calculate the sum of natural numbers up to a given number.  
   Input: n = 5  
   Output: 15

Q13. Write a C# program to reverse a number.  
   Input: 12345  
   Output: 54321

Q14. Write a C# program to check if a number is a palindrome.  
   Input: 121  
   Output: Palindrome

Q15. Write a C# program to check if a number is prime.  
   Input: 13  
   Output: Prime

Q16. Write a C# program to find the greatest common divisor (GCD) of two numbers.  
   Input: 24, 36  
   Output: 12

Q17. Write a C# program to find the least common multiple (LCM) of two numbers.  
   Input: 12, 15  
   Output: 60

Q18. Write a C# program to print the Fibonacci series up to n terms.  
   Input: n = 5  
   Output: 0, 1, 1, 2, 3

Q19. Write a C# program to count the number of digits in a number.  
   Input: 4567  
   Output: 4

Q20. Write a C# program to calculate the power of a number.  
   Input: base = 2, exponent = 3  
   Output: 8

Q21. Write a C# program to check if a character is a vowel or consonant.  
   Input: a  
   Output: Vowel

Q22. Write a C# program to check if a year is a leap year.  
   Input: 2024  
   Output: Leap Year

Q23. Write a C# program to find the sum of the digits of a number.  
   Input: 123  
   Output: 6

Q24. Write a C# program to print all even numbers from 1 to n.  
   Input: n = 10  
   Output: 2, 4, 6, 8, 10

Q25. Write a C# program to print all odd numbers from 1 to n.  
   Input: n = 9  
   Output: 1, 3, 5, 7, 9

Q26. Write a C# program to check if a number is divisible by both 3 and 5.  
   Input: 15  
   Output: Divisible

Q27. Write a C# program to find the ASCII value of a character.  
   Input: A  
   Output: 65

Q28. Write a C# program to calculate the simple interest.  
   Input: P = 1000, R = 5, T = 2  
   Output: 100

Q29. Write a C# program to find the area of a rectangle.  
   Input: Length = 5, Width = 10  
   Output: 50

Q30. Write a C# program to find the perimeter of a rectangle.  
   Input: Length = 5, Width = 10  
   Output: 30

Q31. Write a C# program to find the area of a circle.  
   Input: Radius = 7  
   Output: 153.94

Q32. Write a C# program to find the circumference of a circle.  
   Input: Radius = 7  
   Output: 43.96

Q33. Write a C# program to print the multiplication table of a number.  
   Input: n = 5  
   Output:  
   5 x 1 = 5  
   5 x 2 = 10  
   5 x 3 = 15  
   ...  

Q34. Write a C# program to find the square of a number.  
   Input: 6  
   Output: 36

Q35. Write a C# program to find the cube of a number.  
   Input: 3  
   Output: 27

Q36. Write a C# program to calculate the sum of elements in an array.  
   Input: [1, 2, 3, 4, 5]  
   Output: 15

Q37. Write a C# program to find the maximum number in an array.  
   Input: [10, 20, 5, 7]  
   Output: 20

Q38. Write a C# program to find the minimum number in an array.  
   Input: [10, 20, 5, 7]  
   Output: 5

Q39. Write a C# program to sort an array in ascending order.  
   Input: [3, 1, 4, 2]  
   Output: [1, 2, 3, 4]

Q40. Write a C# program to sort an array in descending order.  
   Input: [3, 1, 4, 2]  
   Output: [4, 3, 2, 1]

Q41. Write a C# program to search for an element in an array.  
   Input: Array = [10, 20, 30], Search = 20  
   Output: Found

Q42. Write a C# program to count the occurrences of an element in an array.  
   Input: Array = [1, 2, 2, 3, 2], Element = 2  
   Output: 3

Q43. Write a C# program to check if a string is a palindrome.  
   Input: madam  
   Output: Palindrome

Q44. Write a C# program to reverse a string.  
   Input: hello  
   Output: olleh

Q45. Write a C# program to count the number of vowels in a string.  
   Input: programming  
   Output: 3

Q46. Write a C# program to check if a string contains a substring.  
   Input: String = "Hello World", Substring = "World"  
   Output: Found

Q47. Write a C# program to find the length of a string.  
   Input: C# Programming  
   Output: 15

Q48. Write a C# program to concatenate two strings.  
   Input: Hello, World!  
   Output: HelloWorld!

Q49. Write a C# program to replace all occurrences of a character in a string.  
   Input: Input = "banana", Replace = 'a', With = 'o'  
   Output: bonono

Q50. Write a C# program to calculate the average of elements in an array.  
   Input: [1, 2, 3, 4, 5]  
   Output: 3

Q51. Write a C# program to remove duplicates from an array.  
   Input: [1, 2, 2, 3, 4, 4, 5]  
   Output: [1, 2, 3, 4, 5]

Q52. Write a C# program to find the second largest number in an array.  
   Input: [10, 20, 5, 7]  
   Output: 10

Q53. Write a C# program to print all prime numbers between 1 and n.  
   Input: n = 10  
   Output: 2, 3, 5, 7

Q54. Write a C# program to find the sum of squares of elements in an array.  
   Input: [1, 2, 3]  
   Output: 14

Q55. Write a C# program to find the frequency of characters in a string.  
   Input: hello  
   Output: h: 1, e: 1, l: 2, o: 1

Q56. Write a C# program to find the smallest positive number missing from an array.  
   Input: [1, 2, 3, 5]  
   Output: 4

Q57. Write a C# program to find the sum of two matrices.  
   Input:  
   Matrix1: [[1, 2], [3, 4]]  
   Matrix2: [[5, 6], [7, 8]]

   Output:  
   [[6, 8], [10, 12]]

Q58. Write a C# program to transpose a matrix.  
   Input:  
   [[1, 2], [3, 4]]

   Output:      
   [[1, 3], [2, 4]]

Q59. Write a C# program to check if a string is an anagram of another.  
   Input: str1 = "listen", str2 = "silent"  
   Output: Anagram

Q60. Write a C# program to find the HCF (GCD) of an array of numbers.  
   Input: [12, 15, 21]  
   Output: 3

Q61. Write a C# program to check if an array is sorted.  
   Input: [1, 2, 3, 4]  
   Output: Sorted

Q62. Write a C# program to reverse an array.  
   Input: [1, 2, 3, 4]  
   Output: [4, 3, 2, 1]

Q63. Write a C# program to merge two arrays.  
   Input: [1, 2], [3, 4]  
   Output: [1, 2, 3, 4]

Q64. Write a C# program to remove all vowels from a string.  
   Input: hello  
   Output: hll

Q65. Write a C# program to count the number of words in a string.  
   Input: C# is fun  
   Output: 3

Q66. Write a C# program to reverse each word in a sentence.  
   Input: C# is fun  
   Output: #C si nuf

Q67. Write a C# program to find the factorial of each element in an array.  
   Input: [2, 3, 4]  
   Output: [2, 6, 24]

Q68. Write a C# program to find the intersection of two arrays.  
   Input: [1, 2, 3], [2, 3, 4]  
   Output: [2, 3]

Q69. Write a C# program to find the union of two arrays.  
   Input: [1, 2, 3], [2, 3, 4]  
   Output: [1, 2, 3, 4]

Q70. Write a C# program to find all permutations of a string.  
   Input: abc

   Output:  
   abc, acb, bac, bca, cab, cba

Q71. Write a C# program to count the number of 1s in the binary representation of a number.  
   Input: 5  
   Output: 2

Q72. Write a C# program to check if a string contains only digits.  
   Input: 12345  
   Output: True

Q73. Write a C# program to generate a random number within a given range.  
   Input: Min = 1, Max = 10  
   Output: Random Number (e.g., 7)

Q74. Write a C# program to find the average of digits in a number.  
   Input: 123  
   Output: 2

Q75. Write a C# program to calculate the product of elements in an array.  
   Input: [2, 3, 4]  
   Output: 24

Q76. Write a C# program to check if two strings are rotations of each other.  
   Input: str1 = "abcd", str2 = "cdab"  
   Output: True

Q77. Write a C# program to count the frequency of words in a string.  
   Input: hello world hello  
   Output: hello: 2, world: 1

Q78. Write a C# program to check if a number is an Armstrong number.  
   Input: 153  
   Output: Armstrong

Q79. Write a C# program to find the longest word in a string.  
   Input: C# is fantastic  
   Output: fantastic

Q80. Write a C# program to print the Pascal's triangle for n rows.  
   Input: n = 5

   Output:  
   1  
   1 1  
   1 2 1  
   1 3 3 1  
   1 4 6 4 1  

Q81. Write a C# program to print a right-angled triangle pattern of *.  
   Input: n = 4  
   Output:  
   *  
   **  
   ***  
   ****  

Q82. Write a C# program to print an inverted right-angled triangle pattern of *.  
   Input: n = 4  
   Output:  
   ****  
   ***  
   **  
   *  

Q83. Write a C# program to print a pyramid pattern of *.  
   Input: n = 4  
   Output:  
      *  
     ***  
    *****  
   *******

Q84. Write a C# program to print a diamond pattern of *.  
   Input: n = 4  
   Output:  
      *  
     ***  
    *****  
   *******  
    *****  
     ***  
      *  

Q85. Write a C# program to print a hollow square pattern of *.  
   Input: n = 4  
   Output:  
   ****  
   *  *  
   *  *  
   ****  

Q86. Write a C# program to print a Floyd's triangle pattern.  
   Input: n = 4  
   Output:  
   1  
   2 3  
   4 5 6  
   7 8 9 10

  
Q87. Write a C# program to print a checkerboard pattern of size n x n.  
   Input: n = 4  
   Output:  
   * * * *  
    * * * *  
   * * * *  
    * * * *  

Q88. Write a C# program to calculate the sum of diagonal elements in a matrix.  
   Input:  
   [[1, 2, 3],  
    [4, 5, 6],  
    [7, 8, 9]]  
     
   Output: 15

Q89. Write a C# program to rotate an array to the left by one position.  
   Input: [1, 2, 3, 4, 5]  
   Output: [2, 3, 4, 5, 1]

Q90. Write a C# program to rotate an array to the right by one position.  
   Input: [1, 2, 3, 4, 5]  
   Output: [5, 1, 2, 3, 4]

Q91. Write a C# program to calculate the sum of the border elements of a matrix.  
   Input:  
   [[1, 2, 3],  
    [4, 5, 6],  
    [7, 8, 9]]  
     
   Output: 28

Q92. Write a C# program to print a hollow pyramid pattern.  
   Input: n = 4  
   Output:  
      *  
     * *  
    *   *  
   *******  

Q93. Write a C# program to count the frequency of each digit in a number.  
   Input: 122333  
   Output:  
   1: 1  
   2: 2  
   3: 3  

Q94. Write a C# program to check if all characters in a string are unique.  
   Input: hello  
   Output: False

Q95. Write a C# program to print a spiral matrix of size n x n.  
   Input: n = 3  
   Output:  
   1 2 3  
   8 9 4  
   7 6 5  

Q96. Write a C# program to find the transpose of a given string matrix.  
   Input:  
   ["abc",  
    "def",  
    "ghi"]  
 
   Output:  
   ["adg",  
    "beh",  
    "cfi"]  

Q97. Write a C# program to check if a number is a perfect number.  
   Input: 28  
   Output: Perfect Number

Q98. Write a C# program to calculate the digital root of a number.  
   Input: 9876  
   Output: 3

Q99. Write a C# program to find the longest increasing subsequence in an array.  
   Input: [10, 22, 9, 33, 21, 50, 41, 60]  
   Output: [10, 22, 33, 50, 60]

Q100. Write a C# program to print Pascal's triangle row-wise for a specific row index.  
   Input: Index = 4  
   Output: [1, 4, 6, 4, 1]