Categories:
.NET (357)
C (330)
C++ (184)
CSS (84)
DBA (2)
General (7)
HTML (4)
Java (574)
JavaScript (106)
JSP (66)
Oracle (114)
Perl (46)
Perl (1)
PHP (2)
PL/SQL (1)
RSS (51)
Software QA (13)
SQL Server (1)
Windows (1)
XHTML (173)
Other Resources:
Will the following program execute? C++
Will the following program execute? C++
✍: Guest
Will the following program execute?
void main()
{
void *vptr = (void *) malloc(sizeof(void));
vptr++;
}
Answer1
It will throw an error, as arithmetic operations cannot be performed on void pointers.
Answer2
It will not build as sizeof cannot be applied to void* ( error “Unknown size” )
Answer3
How can it execute if it won’t even compile? It needs to be int main, not void main. Also, cannot increment a void *.
Answer4
According to gcc compiler it won’t show any error, simply it executes. but in general we can’t do arthematic operation on void, and gives size of void as 1
Answer5
The program compiles in GNU C while giving a warning for “void main”.
The program runs without a crash. sizeof(void) is “1? hence when vptr++, the address is incremented by 1.
Answer6
Regarding arguments about GCC, be aware that this is a C++ question, not C. So gcc will compile and execute, g++ cannot. g++ complains that the return type cannot be void and the argument of sizeof() cannot be void. It also reports that ISO C++ forbids incrementing a pointer of type ‘void*’.
Answer7
in C++
voidp.c: In function `int main()’:
voidp.c:4: error: invalid application of `sizeof’ to a void type
voidp.c:4: error: `malloc’ undeclared (first use this function)
voidp.c:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
voidp.c:6: error: ISO C++ forbids incrementing a pointer of type `void*’
But in c, it work without problems
2012-03-23, 3630👍, 0💬
Popular Posts:
How To Recover a Dropped Index? - Oracle DBA FAQ - Managing Oracle Table Indexes If you have the rec...
Can you explain different software development life cycles -part II? Water Fall Model This is the ol...
When does the compiler not implicitly generate the address of the first element of an array? Wheneve...
How To Control Padding Spaces within a Table Cell? - XHTML 1.0 Tutorials - Understanding Tables and ...
How can I execute a PHP script using command line? Just run the PHP CLI (Command Line Interface) pro...