Rethow exception in c#

vinod kumar

Hi,

What happens when we rethrow an exception in the catch ,who catches that exception.
can anybody give me the example.

thanks,
vinod .

4 Replies

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Vulpes14y ago
Accepted answer
As there's no method earlier in the call stack than the Main() method, the exception cannot be caught and so the application would terminate with a DivideByZeroException.

However, in the following version, there's an outer try/catch statement which can catch the rethrown exception:

static void Main()
{
int x, y, z;

try
{
try
{
x = 1;
y = 0;
z = x/y;
}
catch(DivideByZeroException)
{
throw;
}
}
catch(DivideByZeroException ex)
{
Console.WriteLine(ex.Message + " Caught in outer try statement");
}
vinod kumar14y ago
Hi Vulpes,

Thanks for the replay.It helped me in understanding exception handling.

Thanks.
vinod kumar14y ago
Hi Vulpes,

What happens in the code below ,when catch rethrows exception,does it is unhandled.

static void Main()
{
int x, y, z;
try
{
x=1;
y=0;
z=x/y;
}
catch(DivideByZeroException)
{
throw;
}

}

Thanks.
Vulpes14y ago
When you rethrow an exception it's caught in:

1. A catch block in an enclosing try statement in the same method, if there is one, or if there isn't :

2. By a catch block in a try statement in a method earlier in the call stack.

In the case of 2. the call stack is unwound until a method is found which contains a catch block which can handle the exception. If there is no such method, then the exception will cause the application to terminate.

Here's a simple example.

Although a DivideByZero exception occurs in SomeMethod it's rethrown and caught instead in the Main method from which SomeMethod is called:

using System;

class Program
{
static void Main()
{
try
{
SomeMethod();
}
catch(DivideByZeroException ex)
{
Console.WriteLine(ex.Message + " Caught in Main() method");
}
Console.ReadKey();
}

static void SomeMethod()
{
int x, y, z;

try
{
x = 1;
y = 0;
z = x/y;
}
catch(DivideByZeroException)
{
throw;
}
}
}