Exception Handling (8e6)

14y875Visual Basic .NET

This is Q(6) of the incomplete program. Please complete this program.

using System;
namespace _8e6
{
class Program
{
static void Main(string[] args)
{
IceCreamCone icc1 = IceCreamConeProgram("Orange", 4);
IceCreamCone icc2 = IceCreamConeProgram("Apple", 5);
IceCreamCone icc3 = IceCreamConeProgram("Mango", 6);

Console.WriteLine(icc1.GetFlavor(), icc1.GetScoops());

Console.ReadKey();
}
static IceCreamCone IceCreamConeProgram(string flavor, int scoop)
{
IceCreamCone icc = null;

try
{
icc = new IceCreamCone(flavor, scoop);
}
catch (IceCreamConeException e)
{
Console.WriteLine(e.Message);
}

return icc;
}

class IceCreamConeException : Exception
{
public IceCreamConeException(string flavorAndNoOfScoops) : base(flavorAndNoOfScoops)
{
}

}

class IceCreamCone
{
string iceCreamFlavor;
int scoops;

public IceCreamCone(string iceCreamFlavor, int scoops)
{
this.iceCreamFlavor = iceCreamFlavor;
this.scoops = scoops;
}

public string GetFlavor()
{
if ((iceCreamFlavor != "vanilla") || (iceCreamFlavor != "chocolate") || (iceCreamFlavor != "strawberry") || (iceCreamFlavor != "peach") || (iceCreamFlavor != "banana"))
throw new IceCreamConeException(String.Format("Ice Cream Flavor {0}", iceCreamFlavor));

return this.iceCreamFlavor;
}

public int GetScoops()
{
if (scoops >= 3)
throw new IceCreamConeException(String.Format("No of Scoops {0}", scoops));

return this.scoops;
}

}
}
}

9 Replies

Know the answer? Post it — somebody with the same question will find it here.

14y ago
Thank you for your explanation.
Vulpes14y ago
I mean something that can't be parsed to an integer such as : abc123 or 123.45.

These would throw FormatExceptions if you're using Convert.ToInt32.
14y ago
What is meant by invalid integer?
Vulpes14y ago
The difference is that, if the user enters an invalid integer, the first line will cause the program to blow up with an uncaught exception because you're not told to handle a FormatException in the instructions.

The second line will not have this effect and will, harmlessly, set scoops to zero if an invalid integer is entered.
14y ago
What is the different between using:-

int scoops = Convert.ToInt32(Console.ReadLine());

AND

int.TryParse(Console.ReadLine(), out scoops);
14y ago
Thank you for your explanation.
Vulpes14y ago
The difference is that, for the first 'if' statement, all the sub-conditions need to be true.

For the second 'if' statement, only one of them needs to be true. Moreover when a true sub-condition is found, any remaining ones will not be evaluated at all.

So, the second one (which is what you had originally) is not going to work here. If say the user enters 'chocolate', then the first sub-condition will be true (as it's not 'vanilla') and so the whole expression is true which is not what you what you want.

What you do want is for all the sub-conditions to be true, which is what the first 'if' statement gives you.
14y ago
I couldn't understand the difference between following two:

if ((iceCreamFlavor != "vanilla") && (iceCreamFlavor != "chocolate") && (iceCreamFlavor != "strawberry") && (iceCreamFlavor != "peach") && (iceCreamFlavor != "banana"))

if ((iceCreamFlavor != "vanilla") || (iceCreamFlavor != "chocolate") || (iceCreamFlavor != "strawberry") || (iceCreamFlavor != "peach") || (iceCreamFlavor != "banana"))
Vulpes14y ago
Here's my attempt.

Notice that you're supposed to get input from the user by calling the GetFlavor() and GetScoops() methods from the IceCreamCone class constructor:

using System;
namespace _8e6
{
class Program
{
static void Main(string[] args)
{
IceCreamCone icc1 = IceCreamConeProgram();
IceCreamCone icc2 = IceCreamConeProgram();
IceCreamCone icc3 = IceCreamConeProgram();

Console.ReadKey();
}

static IceCreamCone IceCreamConeProgram()
{
IceCreamCone icc = null;

try
{
icc = new IceCreamCone();
}
catch (IceCreamConeException e)
{
Console.WriteLine(e.Message);
}

return icc;
}

}

class IceCreamConeException : Exception
{
public IceCreamConeException(string flavorAndNoOfScoops) : base(flavorAndNoOfScoops + " is invalid")
{
}

}

class IceCreamCone
{
string iceCreamFlavor;
int scoops;

public IceCreamCone()
{
this.iceCreamFlavor = GetFlavor();
this.scoops = GetScoops();
}

public string GetFlavor()
{

Console.Write("\nEnter ice cream flavor : ");
string iceCreamFlavor = Console.ReadLine().ToLower();
if ((iceCreamFlavor != "vanilla") && (iceCreamFlavor != "chocolate") && (iceCreamFlavor != "strawberry") && (iceCreamFlavor != "peach") && (iceCreamFlavor != "banana"))
throw new IceCreamConeException(String.Format("Ice Cream Flavor {0}", iceCreamFlavor));

return iceCreamFlavor;
}

public int GetScoops()
{
Console.Write("Enter number of scoops : ");
int scoops;
int.TryParse(Console.ReadLine(), out scoops);
if (scoops > 3)
throw new IceCreamConeException(String.Format("No of Scoops {0}", scoops));

return scoops;
}

}
}