First of all you need not headers
#include <string>
#include <cstdlib>
because neither declaration from them is used.
Aslo header
#include <string.h>
should be substituted for
#include <cstring>
In these statements
char* cambia[] = {"ciao "};
char* c[] = {"mondo"};
you defined two arrays each of them having one element of type const char *
. The compiler should issue either an error or a warning because these definitions are not correct. It would be correctly to define the arrays the following way
const char* cambia[] = {"ciao "};
const char* c[] = {"mondo"};
These two statements define arrays of const pointers to string literals. It is undefined behaviour if there ia an attempt to change a string literal in a program. Programs are allowed to place string literals in a read-only memory.
You are right saying that the main problem is in statement
strcat( *cambia, *c );
Function strcat
appends one character array to the end of another character array. So the second cjaracter array must reserve enough memory that accomodates the appended character array. If you even would define correctly array cambia as
char cambia[] = {"ciao "};
it had no enough memory to store also characters of array c.
So before using strcat
you need to reserve enough memory where the concatenated result array would be placed.
You could do this for example the following way
char s[11];
strcpy( s, *cambia );
strcat( s, c );
cout << "s: " << s << endl;
Take into account that instead of character arrays you could use objects of standard class std::string
In this case to append one string to another is made very simply. For example
std::string cambia = "ciao ";
std::string c = "mondo";
cambia += c;
Or
cambia.append( c );