C/C++ literals: By default, a real (floating) numeric literal such as 3.5 is treated as which type?
C Programming
Declarations and Initializations
Difficulty: Easy
Choose an option
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Afloat
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Bdouble
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Clong double
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Dfar double
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ENone of the above
Answer
Correct Answer: double
Explanation
Introduction / Context:Literal types influence overload resolution, precision, and performance. In both C and C++, an unsuffixed real literal like 3.5 is assigned a default floating type unless a suffix changes it. Recognizing this default helps you pick correct function overloads and avoid unintentional narrowing conversions.
Given Data / Assumptions:
- No suffix is present (e.g., 'f' or 'L').
- We refer to standard language rules, not compiler extensions.
- The literal is written in decimal floating notation.
Concept / Approach:
- Unsuffixed floating literals are of type double.
- Adding 'f' or 'F' yields type float; adding 'l' or 'L' yields long double (subject to implementation specifics).
- There is no 'far double' in standard C/C++.
Step-by-Step Solution:
Identify the absence of a suffix → default applies.Default floating literal type → double.Therefore, answer: 'double'.Verification / Alternative check:
Use sizeof(3.5) versus sizeof(3.5f) in C++: commonly 8 bytes vs 4 bytes on typical platforms, confirming different default types.Why Other Options Are Wrong:
- float/long double require explicit suffixes or contexts.
- far double: Not a standard type.
Common Pitfalls:
- Accidentally calling 'float' overloads with double arguments, causing extra casts or ambiguity.
- Assuming 'long double' is always higher precision; implementation details vary.
Final Answer:
double