The following program doesn't output desired data (on VC2008 compiler)
#include <stdio.h>
#include <string.h>
int main(void)
{
int i;
int dest[10] = {1};
int src [] = {2, 3, 4, 5, 6};
memcpy(dest, src, 5);
for (i=0; i<10; i++) printf("%i\n", dest[i]);
return 0;
}
whereas using char arrays instead, every thing goes fine!
where is the problem here?
memcpy takes a number of bytes to copy - not a number of objects.
memcpy(dest,src,5*sizeof(dest[0]))
5 * sizeof dest[0], or sizeof src, may be preferable.memcpy copies bytes only. you need to tell it how many bytes to copy by multiplying the number of objects by the size of each object like so:
memcpy(dest, src, 5 * sizeof(int));
Try memcpy(dest,scr,sizeof(int)*5)
You need to add the sizeof(int):
#include <stdio.h>
#include <string.h>
int main(void)
{
int i;
int dest[10] = {1};
int src [] = {2, 3, 4, 5, 6};
memcpy(dest, src, sizeof(int) * 5);
for (i=0; i<10; i++) printf("%i\n", dest[i]);
return 0;
}
You want to call memcpy with a sizeof( x ) where "x" stands for the object. Here you'd do
memcpy( dest, src, 5*sizeof(int) );
memcpy(dest, src, sizeof src);Better is
memcpy( dest, src, 5*sizeof*src) );
If you change array-type to an other type, the code must not changed.
