Hi, following is the code that i wrote: :happy: Code: #include <stdio.h> int main() { int *ptr; ptr = (int *)malloc(256*256*256*256-1); printf("Sizeof int is %d\n", sizeof(int)); if(ptr == NULL) printf("Allocation failed"); else printf("Allocation succedded"); return 1; } i ran this code on gcc complier. now the warning that i get is ************************* try.c: In function ‘main’: try.c:6: warning: incompatible implicit declaration of built-in function ‘malloc’ try.c:6: warning: integer overflow in expression try.c:6: warning: integer overflow in expression *************************** Q 1) since the sizeof (int) =4 so why integer overflow warning is being displayed??? Q 2) how can i calculate the size of the memory chunck allocated by the malloc function???? ( if i write "ptr = (int *)malloc(256*256*256*256+1000);" even though, i get these warnings and get the output of the program as "Allocation succedded: ):surprised Kindly explain why am i getting the output as mentioned above even though the value mentioned in malloc is overflowing the unsigned int range.. :cryin: thanks in advance
Why do you want to allocate 4GB of RAM? Are you on a 64-bit system? Think about how you might represent 256*256*256*256+1000 in 32 bits. Also think about how 256*256*256*256-1 might be represented, and what the value of the MSB will be, and what malloc will do if it's asked to allocate a negative amount of memory.
