How to convert char to char
Usually I do strcpy but here is looking like I can't copy bigger-sized to lower-sized array. I understand that I need to skip an array element for it, I want to skip first  element but how can I do it? I really don't want to write something alike a=b; a=b... etc.
std::strncpy(a, b + 1, 40);
It will work even if the last character in b is not '\0', or there is '\0' somewhere at index i.
strncpy is particularly useful if a and b are not to be treated as cstring, rather they're just buffer which might or might not contain '\0'.
In C++, you can also use std::copy as:
#include <algorithm> //include this! std::copy(b + 1, b + 41, a); //b + 41 = (b + 1) + 40
I usually prefer std::copy, for it is generic and can be used with any iteratable type.