What is exception handling in C#?

Q: What is exception handling?

Managing runtime errors to maintain program stability.

💡 Concept: Exception Handling in C#

Exception handling is the process of responding to runtime errors or exceptional conditions gracefully to maintain program stability.

📘 Quick Intro

C# provides structured exception handling using try, catch, and finally blocks to catch and manage exceptions.

🧠 Analogy

Think of exception handling like a safety net under a tightrope walker, catching and managing errors to prevent a crash.

🔧 Technical Explanation

⚙️ try block contains code that might throw exceptions.
🛑 catch block handles specific or general exceptions.
🔄 finally block executes code regardless of exceptions (e.g., cleanup).
📜 Exceptions are objects derived from System.Exception.
🔐 Proper handling prevents app crashes and ensures graceful recovery.

🎯 Use Cases

✅ Handling file I/O errors.
✅ Managing database exceptions.
✅ Validating user input.
✅ Ensuring resources are released properly.

💻 Code Example


try {
    int[] numbers = {1, 2, 3};
    Console.WriteLine(numbers[5]);
}
catch (IndexOutOfRangeException ex) {
    Console.WriteLine(""Index out of range error: "" + ex.Message);
}
finally {
    Console.WriteLine(""This block always runs."");
}

❓ Interview Q&A

Q1: What is exception handling?
A: Managing runtime errors to keep programs stable.

Q2: What is the purpose of finally?
A: To execute code regardless of exceptions.

Q3: Can you catch multiple exceptions?
A: Yes, with multiple catch blocks.

Q4: What is a try block?
A: Code that might throw exceptions.

Q5: What base class do exceptions derive from?
A: System.Exception.

Q6: Is exception handling mandatory?
A: No, but recommended for robustness.

Q7: What is the difference between throw and throw ex?
A: throw preserves stack trace; throw ex resets it.

Q8: How to create custom exceptions?
A: Inherit from Exception class.

Q9: What is exception filtering?
A: Catching exceptions conditionally.

Q10: How to ensure resources are disposed?
A: Use finally or using blocks.

📝 MCQs

Q1. What is exception handling?

Ignoring errors
Managing runtime errors
Causing errors
Logging only

Q2. Purpose of finally block?

Executes on error only
Never executes
Always executes code
Executes before try

Q3. Can multiple exceptions be caught?

No
Yes
Sometimes
Never

Q4. What does try block contain?

Code that handles exceptions
Code that may throw exceptions
Cleanup code
Logging code

Q5. Base class for exceptions?

Object
System.Error
System.Exception
System.Class

Q6. Is exception handling mandatory?

Yes
No
Optional
Always required

Q7. Difference between throw and throw ex?

Preserves stack trace
Resets stack trace
Both same
None

Q8. How to create custom exceptions?

Use existing exceptions
Inherit Exception
Override base
Use interface

Q9. What is exception filtering?

Always catch
Conditional catch
Never catch
Log only

Q10. How to ensure disposal?

try block
finally or using
catch block
None

💡 Bonus Insight

Proper exception handling improves application robustness and user experience by gracefully managing errors.

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