PRB: Sizeof Constant Character Returns Different Values (150380)
The information in this article applies to:
- Microsoft Visual C++, 32-bit Professional Edition 4.0
- Microsoft Visual C++, 32-bit Professional Edition 4.1
- Microsoft Visual C++, 32-bit Learning Edition 4.0
This article was previously published under Q150380 SYMPTOMS
The sizeof('x') or sizeof(L'x') constants do not return expected results.
In C, the return value is 4 for the sizeof character constant and 2 for the
sizeof multicharacter constant. In C++, the return value is 1 for the
sizeof character constant and 2 for the sizeof multicharacter constant.
CAUSE
The specification on this point is different for C from what it is for C++.
In C, a character constant is of type int. In C++, a character constant is
of type char. Multicharacter constants are implementation dependent.
RESOLUTION
When using C, do not use sizeof to determine the width of a character
constant. Use sizeof("") to give the width of one character in both C and
C++.
STATUS
This behavior is by design.
REFERENCES
For more information, see "The Annotated C++ Reference Manual" by Margaret
Ellis and Bjarne Stroustrup, Section 2.5.2.
| Modification Type: | Major | Last Reviewed: | 10/24/2003 |
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| Keywords: | kbCompiler kbCRT kbprb KB150380 |
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