Exceptions · interview question

Inside a catch (Exception ex) block, what's the difference between throw; and throw ex;?

Multiple choiceMedium

`throw;` preserves the original stack trace; `throw ex;` resets it to the current line.They're identical.`throw ex;` preserves the stack trace; `throw;` clears it.`throw;` swallows the exception.

Answer and explanation

Correct answer

A. throw; preserves the original stack trace; throw ex; resets it to the current line.

Why

Use throw; to rethrow. If you need to add context, wrap it: throw new OrderException("...", ex); keeps the original as InnerException.

References

Microsoft Learn: Handling and throwing exceptions in .NET

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