Boxing and unboxing: when does it come up?

Question

So I understand what boxing and unboxing is. When\'s it come up in real-world code, or in what examples is it an issue? I can\'t imagine doing something like this example:

Answer 1

Here is a really nasty one :)

SqlCommand cmd = ;

// This code works very well.
int result = (int)cmd.ExecuteScalar();

// This code will throw an exception.
uint result = (uint)cmd.ExecuteScalar();

The second execute fails because it tries to unbox an Int32 into an UInt32 which is not possible. So you have to unbox first and than cast.

uint result = (uint)(int)cmd.ExecuteScalar();