C# exception filter?

Question

Does C# support compiling filters? How do filters even work or what do they do?

Like reflector decompiles a filter as

try
{
}
catch(Exception e) when (?)
{         


        

Answer 1

While catching exceptions, if you want to handle the exceptions differently then you can use Exception Filter
-- After C# 6.0
-- After VB 7.1 Using WHEN

1) C# Sample After C# 6.0

try
{
    throw new CustomException { Severity = 100 };
}
catch (CustomException ex) when (ex.Severity > 50)
{
    Console.WriteLine("*BING BING* WARNING *BING BING*");
}
catch (CustomException ex)
{
    Console.WriteLine("Whooops!");
}

Note : Keep in mind that the order matters

2) C# Sample Before C# 6.0

try
{
    throw new CustomException { Severity = 100 };
}
catch (CustomException ex)
{
   if (ex.Severity > 50)
    {
       Console.WriteLine("*BING BING* WARNING *BING BING*");
    }
   else
    {
       Console.WriteLine("Whooops!");
    }
}

Since this piece of code is equivalent to the previous one. means, they are equivalent, right? --- "But No they are not equivalent"
NOTE : exception filters don’t unwind the stack

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