How to combine two different variables into one?

Question

C++ / C#

for example if int x = 5 ; char y = 'A' ;
and the result was currents
return 5A;

Answer 1

Convert both variables to strings and concatenate them.

Answer 2

int x = 5 ; 
char y = 'A' ; 
char ret[] = { '0'+x, y, '\0' };

that's your whole line
want to return ? ;-) :
return string( ret );