Hi,
I tried the following program :
Though PI has been made const int i am still able to modify its value through a pointer. Why is that?Code:#include<stdio.h> #include<string.h> int main() { const int PI=3; int *ptr; printf("Original Value of PI = %d\n",PI); ptr=&PI; *ptr=4; printf("Value of PI after modification = %d\n",PI); return 0; }
Thanks
If you ignore warnings (either by ignoring the output frome the compiler or not enabling the generation in the first place), then const is not enforced in C.
If you compile the same code in C++, then it will complain that you can't do the conversion from const int * to int *.
With gcc, you get a warning if you use -Wall:
--Originally Posted by GCC
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
Even if you can subvert the compiler to allow you to modify const, don't do it. The compiler may not heed you or you can get strange results.
Plus it would defy the whole purpose of const.
