Is there any way to output the actual array in c++

You can write a simple helper function to allow you to stream the array to an output stream (including but not limited to std::cout):

#include <iostream>
// print an array to an output stream
// prints to std::cout by default
template <typename T, std::size_t N>
void print_array(const T(&a)[N], std::ostream& o = std::cout)
{
  o << "{";
  for (std::size_t i = 0; i < N-1; ++i)
  {
    o << a[i] << ", ";
  }
  o << a[N-1] << "}\n";
}

where a function template is used in order to deduce both the type and size of the array at compile time. You can use it like this:

#include <fstream>
int main()
{
  int a[] = {1,2,3,4,5};
  print_array(a); // prints {1, 2, 3, 4, 5} to stdout

  std::string sa[] = {"hello", "world"};
  print_array(sa, std::cerr); // prints {hello, world} to stderr

  std::ofstream output("array.txt");
  print_array(a, output); // prints {1, 2, 3, 4, 5} to file array.txt
}

This solution can be trivially generalized to deal with ranges and standard library containers. For even more general approaches, see here.

As for the side note, you cannot do that in C++. An array can only hold objects of one type.


Inspired by the answers of juanchopanza and Raxman I decided to do a real IO manipulator, which leads to a syntax like:

const char* arr[] = { "hello", "bye" };
std::cout 
    << "Woot, I can has " << print(arr)
    << " and even " << print(std::vector<int> { 1,2,3,42 }, ":") << "!\n";

printing

Woot, I can has { hello, bye } and even { 1:2:3:42 }!

Note

  • it works seamlessly with chained output streaming using operator<< as usual
  • it is fully generic (supporting any container of streamable types)
  • it even allows to pass a delimiter (as an example)
  • with a little more template arguments it could be made so generic as to work with ostream, wostream etc.

  • fun: Since the delimiter can be any streamable 'thing' as well, you could even... use an array as the delimiter:

    std::cout << "or bizarrely: " << print(arr, print(arr)) << "\n";

    resulting in the rather weird sample output: 

    or bizarrely: { hello{ hello, bye }bye }

    Still demonstrates the power of hooking seamlessly into IO streams, if you ask me.

I believe it will not get much more seamless than this, in C++. Of course there is some implementing to do, but as you can see you can leverage full genericity, so you're at once done for any container of streamable types:

#include <iostream>
#include <vector>

namespace manips
{
    template <typename Cont, typename Delim=const char*>
    struct PrintManip { 
        PrintManip(Cont const& v, Delim d = ", ") : _v(v), _d(std::move(d)) { }

        Cont const& _v;
        Delim _d;

        friend std::ostream& operator<<(std::ostream& os, PrintManip const& manip) {
            using namespace std;
            auto f = begin(manip._v), l(end(manip._v)); 

            os << "{ ";
            while (f != l)
                if ((os << *f) && (++f != l))
                    os << manip._d;
            return os << " }";
        }
    };

    template <typename T, typename Delim=const char*> 
    manips::PrintManip<T, Delim> print(T const& deduce, Delim delim = ", ") { 
        return { deduce, std::move(delim) }; 
    }
}

using manips::print;

int main()
{
    const char* arr[] = { "hello", "bye" };
    std::cout 
        << "Woot, I can has " << print(arr)
        << " and even: " << print(std::vector<int> { 1,2,3,42 }, ':') << "!\n"
        << "or bizarrely: " << print(arr, print(arr)) << "\n";
}

See it live at http://ideone.com/E4G9Fp


for(int i=0;i<9;i++)
cout << anArray[i] << endl;

ahh ok with brackets it be such (simply array print logic for your arrays , u can make it more general in future)

  cout<<'{';
    for(int i=0;i<8;i++)
           cout << anArray[i] <<','; 
    cout<<anArray[8]<<'}';

For python users and c++ lovers there is std::vector .

here how it be print logic for vector //solution with [] operator

if(anVector.size()>=1){
     std::cout<<"{";
      for(int i=0;i<anVector.size()-1;i++){
            std::cout<<anVector[i]<<',' ; 

      }
    std::cout<<anVector[anVector.size()-1]<<'}' ; 
}

//solution with iterator

  std::vector<int>::iterator it =anVector.begin();
       if(it!=anVector.end()){ 
            std::cout << '{'<<*it;
            ++it;
            for (; it != anVector.end(); ++it){
               std::cout<<','<< *it ; 
            }
            std::cout << '}';
        }

Also check C++ 11 std::vector . In new standart initializing and other things more elegant

Tags:

C++

Recent Posts