How to copy array char into string or int* (void *) in c++?

Question

I have more than one char arrays to copy into one string or void * or int *. For example,

char c1[] = "Hello";
char c2[] = "World";
char c3[] = "!!!!";

I want to copy into one int* (void*) or string.

Answer 1

In C++ you can simply use + operator to append strings

string a = "abc";
string b = "dfg";
string c = a + b;
cout << c << endl;

Answer 2

This would be much easier using the std::string and std::stringstream namespace class of C++:

#include <sstream>
#include <string>

std::string c1("Hello");
std::string c2("World");
std::string c3("!!!!");

std::stringstream ss;
ss << c1 << c2 << c3;

std::string finalString = ss.str();

You cannot copy these into an int* or void* because those are completely different types.

Answer 3

In my opinion the simplest way is the following

#include <iostream>
#include <string>
#include <cstring>

int main() 
{
    char c1[] = "Hello";
    char c2[] = "World";
    char c3[] = "!!!!"; 

    size_t n = 0;

    for ( char *t : { c1, c2, c3 } ) n += strlen( t );

    std::string s;
    s.reserve( n );

    for ( char *t : { c1, c2, c3 } ) s += t;

    std::cout << s << std::endl;


    return 0;
}

The output is

HelloWorld!!!!