[Solved] Identify the error in this code snippet:object obj = new StringBuilder(); string s = obj as string; if (s.Length > 0) Console.WriteLine(s); | C Sharp (C#)

C Sharp (C#) - Polymorphism and Abstract Classes

Identify the error in this code snippet:

object obj = new StringBuilder();
string s = obj as string;
if (s.Length > 0) Console.WriteLine(s);

AMissing cast to StringBuilder

BInvalid use of 'as' operator

CStringBuilder cannot be assigned to object

DPossible null reference exception on s.Length

Step-by-Step Solution

Solution:

Step 1: Analyze the 'as' cast result
obj is a StringBuilder, not a string, so 'as string' returns null assigned to s.
Step 2: Identify the error in accessing s.Length
Since s is null, accessing s.Length causes a null reference exception at runtime.
Final Answer:
Possible null reference exception on s.Length -> Option D
Quick Check:
Accessing members on null after 'as' causes exceptions [OK]

Quick Trick: Always check for null after 'as' before member access [OK]

Common Mistakes:

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