Exercise Solutions: Exceptions

Line numbers are for reference. They may not match your code exactly.

Divide by Zero

  • Complete a function called Divide() in Program.cs. The Divide() method takes in two parameters: x and y.

  • Your function should return the result of x/y.

  • However, if y is zero, you should throw an exception.

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   static double Divide(double x, double y)
   {
      if (y == 0.0)
      {
         throw new ArgumentOutOfRangeException("y", "You cannot divide by zero!");
      }
      else
      {
         return x / y;
      }
   }

  • Put your try/catch block in Main() to test out your error-handling skills. If an exception is caught, make sure to print out the error message.

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   try
   {
      Divide(num1, num2);
   }
   catch (ArgumentOutOfRangeException e)
   {
      Console.WriteLine(e.Message);
   }

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Student Test Labs

The CheckFileExtension() function should do the following:

  • Take in one parameter: fileName.

  • Return an integer representing the number of points a student receives for properly submitting a file in C#.

  • If a student’s submitted file ends in .cs, they get 1 point.

  • If a student’s submitted file doesn’t end in .cs, they get 0 points.

  • If the file submitted is null or an empty string, an exception should be thrown. What kind of exception is up to you!

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   static int CheckFileExtension(string fileName)
   {
      if (fileName == null || fileName == "")
      {
         throw new ArgumentNullException("fileName","Student did not submit any work!");
      }
      else
      {
         if (fileName.Substring(fileName.Length - 3, 3) == ".cs")
         {
            return 1;
         }
         else
         {
            return 0;
         }
      }
   }

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