15 C# Questions on For, While and If Else Statements

Meenakshi Agarwal
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Meenakshi Agarwal
Hi, I'm Meenakshi Agarwal. I have a Bachelor's degree in Computer Science and a Master's degree in Computer Applications. After spending over a decade in large...
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15 C# Questions - Loops

Check out 15 C# Questions – For, While Loops, and If Else Statements. These questions will help you to test and improve your C# programming skills.

Loops and conditional constructs are an integral part of any programming language. So you need to know how to use them efficiently to produce scalable and quality. A good programmer should be able to decide when to choose a for loop and when should he prefer the while loop.

But before you move to the questions and answers section, please check below if you’ve not read the basic differences between the two types of loops. Also, if you are aware of any other differences, then do let us know as well.

For Vs While Loops in C#

There is a semantic difference between a for and while loop which you must understand. While loops are meant to handle an indefinite number of iterations. So you should use it in cases like while reading a file to its EOF. Whereas, the for loops are more appropriate to tackle definite no. of operations. For example – traversing through the elements in a list.

Similarly, there are ways to use an if…else block so that your code can produce correct results with minimum iterations.

Let’s now begin to read the top 15 C# questions – for, while loops and conditional operators.

C# Questions – For, While Loops, and If Else

C# Questions - For, While Loops and If Else Statements.
15 C# Questions – Loops

Q-1. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)

     {
     int i;
     int div = 8, num = 32;
     for (i = 0; i <= 10; i++)
     {
         if ((num / div * 3)== 6)
         {
             Console.WriteLine( i + " ");
             continue;
         }
         else if (i != 5)
             Console.Write(i + " ");
         else
             break;
    }
    Console.ReadLine();
    }
   }
}

Output:

A. 1 2 3 4 5 6 7 8 9 10
B. 0 1 2 3 4 5 6 7 8 9 10
C. 0 1 2 3 4 5
D. 0 1 2 3 4

Show Answer

Option – D

Q-2. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)

     {
     int i = 30;
     int j = 5 % 5;
     if (Convert.ToBoolean(Convert.ToInt32(i != j)))
     {
         Console.WriteLine("if clause executed");
     }
     else
     {
         Console.WriteLine("else clause executed");
     }
     Console.WriteLine("Entered Main Function");
     Console.ReadLine();
    }       
    }
}

Output:

A. If clause executed
B. else clause executed
C. If clause executed
Entered Main Function
D. else clause executed
Entered Main Function

Show Answer

Option – C

Q-3. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
      int a, b;
      for (a = 2; a >= 0; a--)
      {
          for (b = 0; b <= 2; b++)
          {
              if (a == b)
              {
                  Console.WriteLine("1");
              }
              else
              {
                  Console.WriteLine("0");
              }
         }
         Console.WriteLine("\n");
       }
     }
   }
}

Output:

A. 1 0 0
0 1 0
0 0 1
B. 0 1 0
1 0 0
0 0 1
C.  0 0 1
0 1 0
1 0 0
D. 1 0 0
0 0 1
0 1 0

Show Answer

Option – C

Also Read: 15 C# Subjective Questions and Answers

Q-4. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
       int val = 5;
       if (Convert.ToBoolean((.002f) -(0.1f)))
          Console.WriteLine("The 'if condition' executed");
       else if (val == 5)
          Console.WriteLine("The 'else if' executed");
       else
          Console.WriteLine("The 'else clause' executed");
       Console.ReadLine();
     }
    }
}

Output:

A. The ‘if condition’ executed
B. The ‘else if’ executed
C. The ‘else clause’ executed
D. Error

Show Answer

Option – A

Q-5. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
      int a = -2;
      int b = -1;
      if (Convert.ToBoolean (++a = ++b))
      Console.WriteLine("If Condition is True");
      else
      Console.WriteLine("If Condition is False");
      Console.ReadLine();
     }
    }
}

Output:

A. If Condition is True
B. If Condition is False
C. Compile Time Error
D. Runtime Error

Show Answer

Option – C

Q-6. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
      if (Convert.ToBoolean(Convert.ToInt32(0xB)))
      if (Convert.ToBoolean(Convert.ToInt32(022)))
      if (Convert.ToBoolean(Convert.ToInt32('\xeb')))
      Console.WriteLine("If executed Successfully");
      else ;
      else ;
      else ;
      }
    }
}

Output:

A. Compile time error: Misplaced else
B. Compile time error: Undefined symbol
C. If executed Successfully
D. Nothing is printed.

Show Answer

Option – C

Q-7. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
      int a = 1, b = 2;
     if (Convert.ToBoolean(Convert.ToInt32(++a)) || Convert.ToBoolean(Convert.ToInt32(++b)))
     {
         Console.WriteLine(a + "\n" + b);
     }
     else
     Console.WriteLine(" C# questions ");
      }
    }
}

Output:

A. 1 2
B. 2 2
C. 2 3
D. 2 4

Show Answer

Option – B

Q-8. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
     int i;
     i = 0;
     while (i++ < 5)
     {
         Console.WriteLine(i);
     }
     Console.WriteLine("\n");
     i = 0;
     while ( ++i < 5)
    {
        Console.WriteLine(i);
    }
    Console.ReadLine();
      }
    }
}

Output:

A. 1 2 3 4
1 2 3 4 5
B. 1 2 3
1 2 3 4
C. 1 2 3 4 5
1 2 3 4
D. 1 2 3 4 5
1 2 3 4 5

Show Answer

Option – C

Q-9. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
     int num= 1234, r;
     while (num > 0)
      {
          r = num % 10;
          num = num / 10;
          Console.WriteLine(+r);
      }
      
      }
    }
}

Output:

A. 1 2 3 4
B. 4 3 2 1
C. 2 3 4 1
D. 3 2 4 1

Show Answer

Option – B

Q-10. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
      int i = 1, j = 1;
      while (++i <= 10)
      {
          j++;
      }
      Console.WriteLine(i+ "  " +j);
      }
    }
}

Output:

A. 12 11
B. 10 11
C. 11 12
D. 11 10

Show Answer

Option – D

Q-11. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
     int val = 1;
      switch (val << 2 + val)
      {
      default: 
          Console.WriteLine("First");
          break;
      case 4: 
          Console.WriteLine("Second");
          break;
      case 5: 
          Console.WriteLine("Third");
          break;
      case 8: 
          Console.WriteLine("Fourth");
          break;
      case 9: 
          Console.WriteLine("Fifth");
          break;    
      }
      Console.ReadLine();
      }
    }
}

Output:

A. First
B. Second
C. Third
D. Fourth
E. Fifth

Show Answer

Option – D

Q-12. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
    int const c = 2;
       switch (c)
       {
       case c: 
           Console.WriteLine("A");
           break;
       case c * 1:
           Console.WriteLine("B");
           break;
       case c - 2:
           Console.WriteLine("C");
           break;
       default: 
           Console.WriteLine("D");
       }
    }
    }
}

Output:

A. A
B. B
C. C
D. D
E. Compilation Error cannot use const

Show Answer

Option – E

Also Read: 15 C# Coding Related Questions and Answers

Q-13. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
     int a = 2, b = 3, c = 4;
     switch (a + b - c)
     {
     case 0: case 2: case 4:
         ++a;
         c += b;
         break;
     case 1: case 3: case 5 :
         --a;
         c -= b;
         break;
     default:
         a += b;
         break;
     }
     Console.WriteLine(a + "\n" + b + "\n" + c);
     }
    }
}

Output:

A. 1 3 1
B. 2 3 4
C. 5 3 4
D. Compilation Error

Show Answer

Option – A

Q-14. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
       int i = 1, j = 5;
    do
    {
        Console.WriteLine(i = i++ * j);
    }while (i <= 10);
     }
    }
}

Output:

A. 5 25
B. 5 10 15 20 25 30 35 40 45 50
C. 25 30
D. 5 11 16 21 26 31 36 41 46 51

Show Answer

Option – A

Q-15. What will be the output of the following code snippet:

using System;
namespace ProgrammingExercise
{
class FindOutput
    {
     static void Main(string[] args)
     {
       int a;
       for (a = 10; a <= 15; a++)
       while (Convert.ToBoolean(Convert.ToInt32(a)))
       {
        do
        {
            Console.WriteLine(1);
            if (Convert.ToBoolean(a >> 1))
            continue;
        }while (Convert.ToBoolean(0));
        break;
       }
     }
    }
}

Output:

A. 0 0 0……infinite times
B. 1 1 1 1…..infinite times
C. 1 1 1 1 1 1
D. Exception

Show Answer

Option – C

Before You Leave

We hope you have enjoyed the above set of questions. Here, we’ve tried to cover all types of loops and conditional statements that C# language supports.

If you like to share any feedback or an idea about a post, then use the comment box and let your voice reach us. Check out more CSharp Q&A on various programming topics:

1. 50 CSharp Coding Interview Questions
2. 15 CSharp Programming Interview Questions
3. 15 CSharp Interview Questions Every Programmer
4. 15 CSharp Questions on For, While, and If Else
5. 15 CSharp Programming Questions on Classes
6. 20 CSharp OOPS Interview Questions Set-1
7. 20 CSharp OOPS Interview Questions Set-2
8. 25 CSharp OOPs Interview Questions Set-3
9. 35 CSharp Exception Handling Questions

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All the Best,
TechBeamers.

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