Concatenating strings in C, which method is more efficient?

Question

I came across these two methods to concatenate strings:

Common part:

char* first= \"First\";
char* second = \"Second\";
char* both = malloc(strlen(fi         


        

Answer 1

I don't know that in case two there's any real concatenation done. Printing them back to back doesn't constitute concatenation.

Tell me though, which would be faster:

1) a) copy string A to new buffer b) copy string B to buffer c) copy buffer to output buffer

or

1)copy string A to output buffer b) copy string b to output buffer