How can you safely extract a string from an object and convert it to uppercase using pattern matching?

hard🚀 Application Q9 of 15

C Sharp (C#) - Polymorphism and Abstract Classes

How can you safely extract a string from an object and convert it to uppercase using pattern matching?

Avar upper = ((string)obj).ToUpper();

Bif (obj is string s) { var upper = s.ToUpper(); }

Cif (obj as string s) { var upper = s.ToUpper(); }

Dvar upper = obj.ToString().ToUpper();

Step-by-Step Solution

Solution:

Step 1: Use pattern matching to check and assign
if (obj is string s) safely checks type and assigns s.
Step 2: Call ToUpper() on s
This avoids exceptions if obj is not a string.
Final Answer:
if (obj is string s) { var upper = s.ToUpper(); } -> Option B
Quick Check:
Safe extraction and use = B [OK]

Quick Trick: Use 'is string s' to avoid invalid cast exceptions [OK]

Common Mistakes:

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