Can I catch multiple exceptions in one block?

Yes, using 'when' filters or pattern matching in C#.

How do I avoid duplicating catch logic?

You can route exception handling to a common method like Handle(ex).

Catching Multiple Exceptions in .NET | FullStackPrep.Dev

💡 Concept Name

Multiple Exception Handling in .NET

📘 Quick Intro

.NET allows clean handling of multiple exceptions without duplicating catch blocks using modern C# features like when filters and pattern matching.

🧠 Analogy / Short Story

Imagine you're sorting errors into folders. Instead of having a separate folder for each error type with the same content, you drop all similar issues into one shared "general issues" folder—saving time and space.

🔧 Technical Explanation

✅ Use catch (Exception ex) when (...) to filter types in one block.
✅ C# 7+ allows is pattern matching: ex is X or Y.
✅ Centralize repeated logic in a shared method: Handle(ex).
✅ C# 8+ supports switch expressions for flexible case-based logic inside catch.

🎯 Purpose & Use Case

✅ Clean error handling for apps interacting with I/O, databases, and APIs.
✅ Centralized logging for observability.
✅ Reusability across large enterprise projects.

💻 Real Code Example

try
{
    // Risky operations
}
catch (Exception ex) when (ex is IOException || ex is SqlException)
{
    Handle(ex);
}

void Handle(Exception ex)
{
    Console.WriteLine($""Caught: {ex.GetType().Name}"");
    // Additional logic/logging
}

❓ Interview Q&A

Q1: How do you handle multiple exceptions in one catch?
A: Use when filters or pattern matching.

Q2: What’s the benefit of this approach?
A: Cleaner code and no duplication.

Q3: Can this be used with logging?
A: Yes — centralize logic in a shared method.

Q4: What version introduced pattern matching?
A: C# 7.0.

Q5: Is `switch` usable in catch?
A: Yes, to match exception types.

📝 MCQs

Q1. What keyword helps filter exception types in a catch block?

if
where
when
case

Q2. Which C# version introduced pattern matching?

C# 5
C# 6
C# 7.0
C# 8.0

Q3. What is a benefit of shared exception handlers?

Harder to debug
Longer code
Code reusability
None

Q4. How do you avoid duplication in exception blocks?

Write longer code
Use unsafe blocks
Use a common handler method
Try multiple times

Q5. Which exceptions can be grouped using `when`?

Only IOExceptions
Only SqlExceptions
Any .NET exceptions
Only system exceptions

💡 Bonus Insight

Combine when filters with structured logging (e.g., Serilog) to capture and categorize error types dynamically with minimal overhead.

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Catching Multiple Exceptions in .NET