Working through Teach Yourself C in my spare time and am now in chapter 5 which deals with arrays and strings. My question is fairly obvious but the author does not seem to address it in his treatment of strcat(). What I want to know is this: all strings contain a null character at the end, which strlen() does not return. When using strcat() to combine two strings, are both null characters preserved? Or is one of them lost, so that only one null character exists at the end of the new, larger string? Thanks in advance for your time and patience in answering this novice's question.