[Solved] What will be the output of this code?try { throw new ArgumentNullException(); } catch (ArgumentException ex) when (ex.ParamName == "id") { Console.WriteLine("Caught ArgumentException with id");... | C Sharp (C#)

C Sharp (C#) - Exception Handling

What will be the output of this code?

try {
    throw new ArgumentNullException();
} catch (ArgumentException ex) when (ex.ParamName == "id") {
    Console.WriteLine("Caught ArgumentException with id");
} catch (ArgumentException) {
    Console.WriteLine("Caught ArgumentException");
}

ACaught ArgumentException

BCaught ArgumentException with id

CNo output, program crashes

DCompilation error

Step-by-Step Solution

Solution:

Step 1: Check exception type and when condition
The thrown exception is ArgumentNullException, which is a subclass of ArgumentException. The when condition checks ex.ParamName == "id", but ParamName is null by default.
Step 2: Evaluate which catch block runs
The first catch block's when condition is false (null != "id"), so it skips. The second catch block catches all ArgumentException without condition and runs.
Final Answer:
Caught ArgumentException -> Option A
Quick Check:
when false skips catch, next catch runs [OK]

Quick Trick: when false skips catch, next matching catch runs [OK]

Common Mistakes:

MISTAKES

Assuming when condition is true by default
Expecting first catch to run always
Confusing exception types

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What will be the output of this code?

Step 1: Check exception type and when condition

Step 2: Evaluate which catch block runs

Final Answer:

Quick Check:

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