---
title: "C# exceptions: try, catch, finally and good habits"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source: https://iinventedlight.com/library/notes/csharp-exceptions.md
source_license: "CC BY 4.0 (dotnet/docs); restated in our own words"
attribution: "Summary by iinventedlight (AI-assisted). Sources: Microsoft Learn, Exceptions and Exception Handling - C#, CC BY 4.0 (dotnet/docs); Microsoft Learn, Best practices for exceptions - .NET, CC BY 4.0 (dotnet/docs)."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-04
status: published
checked_on: 2026-11-04
as_of: 2026-11-04
confidence: medium
untested: "No code was run; only the fetched documentation pages were read."
category: coding-references
topic_area: "csharp: error handling"
tags: csharp, dotnet, exceptions, error-handling
sources:
  - id: S1
    title: "Exceptions and Exception Handling - C#"
    publisher: Microsoft Learn
    url: https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/exceptions/
    accessed: 2026-11-04
    license: "CC BY 4.0 (dotnet/docs)"
  - id: S2
    title: "Best practices for exceptions - .NET"
    publisher: Microsoft Learn
    url: https://learn.microsoft.com/en-us/dotnet/standard/exceptions/best-practices-for-exceptions
    accessed: 2026-11-04
    license: "CC BY 4.0 (dotnet/docs)"
---
# C# exceptions: try, catch, finally and good habits

## Short answer
Put risky code in `try`, handle errors you can recover from in `catch`, and release resources in `finally`, which runs whether or not an exception occurs. [S1][S2]

## Good habits
- Catch only what you can handle; letting an app crash beats hiding a bug. [S2]
- Rethrow with `throw;` to keep the original stack trace. [S2]
- Design APIs so common failures do not need exceptions (for example `TryParse`). [S2]
- Prefer `using` for disposable objects.

## Claims
- id: C1
  claim: Exceptions derive from System.Exception.
  source: S1
  evidence: "Exceptions are types that all ultimately derive from System.Exception."
- id: C2
  claim: finally runs regardless of exceptions.
  source: S1
  evidence: "Code in a finally block is executed regardless of if an exception is thrown."
- id: C3
  claim: A crashed app beats one with undefined behavior.
  source: S2
  evidence: "a crashed app is more reliable and diagnosable than an app"
- id: C4
  claim: Classes should be designed to avoid exceptions.
  source: S2
  evidence: "Design classes so that exceptions can be avoided"

## Sources
- [S1] Exceptions and Exception Handling - C#. Microsoft Learn. https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/exceptions/ . License: CC BY 4.0 (dotnet/docs). Accessed 2026-11-04.
- [S2] Best practices for exceptions - .NET. Microsoft Learn. https://learn.microsoft.com/en-us/dotnet/standard/exceptions/best-practices-for-exceptions . License: CC BY 4.0 (dotnet/docs). Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).