Question

Write a program to test the difference between %d and %i conversion

Answer 1

Void test(char *s)
{
  int i, d;
  sscanf(s, "%i", &i);
  printf("%s converts to %i using %%i\n", s, i);
  sscanf(s, "%d", &d);
  printf("%s converts to %d using %%d\n", s, d);
}

int main()
{
  test("123");
  test("0x123");
  return 0;
}

outputs:
123 converts to 123 using %i
123 converts to 123 using %d
0x123 converts to 291 using %i
0x123 converts to 0 using %d

As you can see, %i is capable of parsing hexadecimal, whereas %d is not. For printf they're the same.