4 ms·

I come from a photography and design background, and I've tended to naturally write code much like the author is suggesting. However, the for loop is mystifyin

• maxerickson 13y ago
  Well, I guess you expect that it is copying something. It is implemented using C pointers, which enjoy a reputation of being difficult to explain. For example: http://stackoverflow.com/questions/15151377/what-exactly-is-a-c-pointer-if-not-a-memory-address http://stackoverflow.com/questions/15151377/what-exactly-is-... Accepting some level of fuzziness, the ++ parts are moving through two spots in memory, the * parts are copying the contents of the one to the other. It all goes 1 byte at a time. (I apologize if my assumption that you are not familiar with C is off base)
• gknoy 13y ago
  for (; (*to = *from) != 0; ++from, ++to) to and from are pointers to characters. When we increment them, we point to the next memory location in each string. "hello" // a sequence of bytes with a zero marking the end ^-- to In our loop, we don't need to allocate any helper variables, and can just increment our pointers to point to the next memory slot in each string. I'm not a C expert, so I may get this subtly wrong, but I believe this is equivalent to: do { *to = *from; // copy character from source to destination } while (0 != *to); // until we reach the '\0' terminator