Difficulty: Easy
Correct Answer: const float pi = 3.14F;
Explanation:
Introduction / Context:Constants in C# are compile-time values that cannot change after compilation. This question asks which syntax properly defines an immutable numeric constant.
Given Data / Assumptions:
Concept / Approach:Use const for compile-time constants. A const must be assigned at declaration. #define in C# only defines a conditional compilation symbol, not a numeric macro as in C/C++.
Step-by-Step Solution:
Option C: const float pi = 3.14F; — Correct. Immutable at compile-time and accessible where in scope. Option A: float pi = 3.14F; — Mutable variable, not a constant. Option B: #define pi 3.14F; — Invalid in C# for numeric macros; #define only declares symbols. Option D: Split const declaration and assignment — illegal; const must be assigned inline. Option E: Assignment with no declaration — invalid.Verification / Alternative check:Attempting to reassign pi when declared const produces a compile-time error, proving immutability.
Why Other Options Are Wrong:They either define mutable data or use invalid/unsupported syntax.
Common Pitfalls:Confusing const with readonly (readonly allows assignment in constructor at run time; const is compile-time).
Final Answer:const float pi = 3.14F;
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