Concatenating strings of different types in C++ -

how can concatenate following char , tchar variables in c++?

tchar filename[50];  tchar prefix[5] = "file_"; tchar ext[4] = ".csv"; char *id[10]; generateid(*id); 

the generateid(char *s) function generates random string. need end filename being file_randomidgoeshere.csv

i have tried strncat(filename, prefix, 5); works fine tchar variables not char * requires const char * instead, maybe there's better way of doing it, not sure how convert char * or char ** const char *.

any ideas?

the error strncat(filename, id, 10) error: cannot convert 'char**' 'const char*'

the first thing should is, since using c++ , not pure c, use string class represent strings , manage them in way more convenient raw c-style character arrays.

in context of windows c++ programming, cstring convenient string class.
can use overloaded operator+ (or +=) concatenate strings in convenient, robust , easy way.

if have id stored in char string (as ascii string), showed in question's code:

char id[10];   generateid(id); 

you can first create cstring around (this convert char-string tchar-string, in particular wchar_t-string if using unicode builds, have been default since vs2005):

const cstring strid(id); 

then, can build whole file name string:

// // build file name using format: // //    file_<generatedidgoeshere>.csv // cstring filename(_t("file_")); filename += strid; filename += _t(".csv"); 

as alternative, use cstring::format method, e.g.:

cstring filename; filename.format(_t("file_%s.csv"), strid.getstring()); 

you can pass instances of cstring lpctstr parameters in win32 apis, since cstring offers implicit conversion lpctstr (i.e. const tchar*).

to use cstring, can #include <atlstr.h>.