C#.NET — Choose the correct method declaration for: accepts (int, Single, double) and returns decimal. If a procedure fun() is to receive an int, a Single, and a double, and it must return a decimal, which of the following is the correct way to define it?
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Afun(int i, Single j, double k) decimal { ... }
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Bstatic decimal fun(int i, Single j, double k) { ... }
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Cfun(int i, Single j, double k) { ... return decimal; }
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Dstatic decimal fun(int i, Single j, double k) decimal { ... }
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EA procedure can never return a value.
Answer
Correct Answer: static decimal fun(int i, Single j, double k) { ... }
Explanation
Introduction / Context:This item focuses on C# method signature syntax: placement of the return type, optional static modifier, correct parameter types, and valid return statements.
Given Data / Assumptions:
- Parameters: int, Single (System.Single), double.
- Return type: decimal.
- Method name: fun.
Concept / Approach:In C#, the syntax is: [modifiers] return_type MethodName(parameters) { body }. The return type precedes the method name. System.Single is the CLR type for float, and is valid in signatures. The method may be static or instance; both compile; the choice here uses static and is syntactically correct.
Step-by-Step Solution:
Check option A: places return type after the parameter list — invalid in C#. Option B: “static decimal fun(int i, Single j, double k) { ... }” — correct placement and valid types. Option C: uses “return decimal;” — invalid; you must return a decimal value, not a type name. Option D: repeats the return type after the header — invalid. Option E: incorrect; C# methods can return values.Verification / Alternative check:Compiling a stub with option B succeeds. Replacing Single with float also works, since float is the C# keyword alias for System.Single.
Why Other Options Are Wrong:
- A/D: wrong placement of the return type.
- C: misuse of type name in return statement.
- E: factually false.
Common Pitfalls:Confusing C# with languages that place return types elsewhere; forgetting that Single is valid; or thinking that methods must be static (they do not).
Final Answer:static decimal fun(int i, Single j, double k) { ... }