Concatenate char arrays in C++ - c++

Question

I have the following code and would like to end up with a char such as: "Hello, how are you?" (this is just an example of what I'm trying to achieve)
How can I concatenate the 2 char arrays plus adding the "," in the middle and the "you?" at the end?
So far this concatenates the 2 arrays but not sure how to add the additional characters to my final char variable I want to come up with.
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
char foo[] = { "hello" };
char test[] = { "how are" };
strncat_s(foo, test, 12);
cout << foo;
return 0;
}
EDIT:
This is what I came up with after all your replies. I'd like to know if this is the best approach?
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
char foo[] = { "hola" };
char test[] = { "test" };
string foos, tests;
foos = string(foo);
tests = string(test);
string concat = foos + " " + tests;
cout << concat;
return 0;
}

Answer 1

In C++, use std::string, and the operator+, it is designed specifically to solve problems like this.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string foo( "hello" );
string test( "how are" );
cout << foo + " , " + test;
return 0;
}

Answer 2

Best thing is use std::string in C++ as other answers. If you really need to work with char try this way. didn't tested.
const char* foo = "hello";
const char* test= "how are";
char* full_text;
full_text= malloc(strlen(foo)+strlen(test)+1);
strcpy(full_text, foo );
strcat(full_text, test);

Answer 3

If you dont want to use string you can do it simply by taking an other array and storing both arrays in it with loop
#include<iostream>
#include<stdlib.h>
#include<cstdio>
using namespace std;
int main(){
char fname[30],lname[30],full_name[60];
int i,j;
i=0;j=0; // i is index of fname and j is index for lname
cout<<"Enter your first name: ";
gets(fname);
cout<<"Enter your last name: ";
gets(lname);
for (i;fname[i]!='\0';i++){
full_name[i] = fname[i];
}
cout<<"i ="<<i;
full_name[i]=' ';
i = i + 1;
for (i,j;lname[j]!='\0';i++,j++){
full_name[i] = lname[j];
}
cout<<"Your full name is: "<<full_name<<endl;
system("pause");
return 0;
}

Answer 4

Yes, in C++ use the + operator for string concatenation.
But this will not work:
char[] + char[] + char[]
convert one array to std::string and it will:
std::string(char[]) + char[] + char[]
E.g.:
#include <iostream>
int main()
{
const char a[] = "how ";
const char b[] = "are ";
const char c[] = "you ";
std::cout << std::string( a + b + c ) << "\n"; // Error
std::cout << std::string(a) + b + c << "\n"; // Fine
}

Answer 5

If performance is a concern for you, I would suggest avoiding std::string. Instead, you can use the character array.
template <typename Result>
void concatenate(Result *res)
{
return;
}
template <typename Result, typename T>
void concatenate(Result *res, T *str)
{
strcat(res, str);
}
template <typename Result, typename First, typename ... T>
void concatenate(Result *res, First *f, T* ... next)
{
strcat(res, f);
concatenate(res, next...);
}
template <typename Result, typename First, typename ... T>
void concatStrings(Result *res, First *f, T* ... next)
{
strcpy(res, f);
concatenate(res, next...);
}
And then, you can call the concatStrings function with at least two parameters and at most as many you need.
/* You can remove constexpr as per your need. */
constexpr char hello[6] = "hello";
constexpr char sep[2] = ",";
constexpr char how[5] = " how";
constexpr char are[5] = " are";
constexpr char you[6] = " you?";
auto totalSize = strlen(hello) + strlen(sep) + strlen(how) + strlen(are) + strlen(you) + 5;
char statement[totalSize];
concatStrings(statement, hello, sep, how, are, you);
std::cout << statement << '\n';

Answer 6

cout<<x<<y<<z<<" ";
char arr[3] = {x , y ,z};
ans.push_back(arr);
if you want to push in vector array.

Answer 7

FOR 2 CHAR ARRAYS
char foo[] = { "hello " };
char test[] = { "how are" };
char concat[50];
char x='X'; //Any Temporary Variable
int i;
for(i=0; x!='\0'; i++){ //x is not NULL
x = foo[i];
concat[i] = x;
}
x = 'D';
i--;
for (int k = 0; x!='\0'; i++){
x = test[k];
concat[i] = x;
k++;
}
cout<<"Concat Array is: "<<concat;