C语言实例

• 编译环境：Visual Studio 2012
• 编程语言：C

1、memcpy与’/0’

int main(void) {
  char* p1 = "abc";
  char* p2 = (char*)malloc(sizeof(char) * 3);
  char* p3 = (char*)memcpy(p2, p1, 3);
  printf("p2 = %s\np3 = %s\n", p2, p3);
  free(p2);
  p2 = NULL;
  p3 = NULL;
  system("pause");
  return 1;
}

打印结果：乱码

p2 = abc?
p3 = abc?
请按任意键继续. . .

---

int main(void) {
  char* p1 = "abc";
  char* p2 = (char*)malloc(sizeof(char) * 4);
  char* p3 = (char*)memcpy(p2, p1, 4);
  printf("p2 = %s\np3 = %s\n", p2, p3);
  free(p2);
  p2 = NULL;
  p3 = NULL;
  system("pause");
  return 1;
}

打印结果：正常

p2 = abc
p3 = abc
请按任意键继续. . .