{char src[] = "******************************";char dest[] = "abcdefghijlkmnopqrstuvwxyz0123456709";char *ptr;printf("destination before memcpy: %s", dest);ptr = memcpy(dest, src, strlen(src));printf("ptr = %d", ptr);if (ptr)printf("destination after memcpy: %s", dest);elseprintf("memcpy failed");return 0;}上面這段程序中printf("ptr = %d", ptr);打印出ptr=42，可memcpy函數(shù)返回的是指向dest的指針，為什么這里是42呢？另外如果打印出strlen(src)的話是30，那src的結(jié)束標(biāo)記符"\n"不算src的長(zhǎng)度么？謝謝！