Notes for C/C++ Programming Notes for C/C++ Programming Off by One Error Prone # define LEN 128 char buf [ LEN ] = { 0 } ; // -1 for prevent missing NULL terminator // since strncpy doesn't preserve it for us. strncpy ( buf , something , sizeof ( buf ) - 1 ) ; // snprintf does preserve NULL terminator for us // i.e. actual size for placing characters is sizeof(buf) - 1 // but it takes extra time to parsing format snprintf ( buf , sizeof ( buf ) , something ) ; Bad things often happen when we mess with -1 or +1 to pointers point to continuous elements. Absorber # define LEN 128 char buf [ LEN + 1 ] = { 0 } ; // ^^^^ Always preserve 1 byte strncpy ( buf , somethin , sizeof ( buf ) ) ; Constant Correctness (C/C++) Bad void do_something ( char * dest , char * src ) ; struct MyList { void do_something ( std :: string & name ) ; } ; Reason : Will the name be modified by the lookup method? Will stat