Array of int or vector?

Question

i'm trying to store some elements that is going to change every time, but i don't know which

way is better and why. I'm thinking about two ways, 1) declaring array of int and loop or

use vector's.

Which way is better and why?

Does declaring array of int have any future memore problems as leak?

the code down below show the two ways i'm talking about:

1)

#include <iostream>
#include <vector>


int main()
{

     int x[5];

     x[0] = 10;
     x[1] = 20;
     x[2] = 30;
     x[3] = 40;
     x[4] = 50;


for(unsigned int i = 0;i<=sizeof(x[5]); i++)
    {


     std:: cout << "x[" << i << "] = "<< x[i] << std::endl;

}

system("pause");

    return 0;
}

2)

#include <iostream>
#include <vector>


int main()
{

    std::vector<int> x;

    x.push_back(10);
    x.push_back(20);
    x.push_back(30);
    x.push_back(40);
    x.push_back(50);


for(unsigned int i = 0;i<=x.size()-1; i++)
    {


     std:: cout << "x[" << i << "] = "<< x[i] << std::endl;

}

system("pause");

    return 0;
}

Answer 1

If this is all you have to do, and your array will always have a size that is known at compile time, then you do not need std::vector.

On the other hand, in C++11 you could use std::array instead of a plain C array (std::array is a zero-overhead, safer and more functional wrapper over a C array):

#include <iostream>
#include <array>

int main()
{
     std::array<int, 5> x = { 10, 20, 30, 40, 50 };
     for (unsigned int i = 0; i < x.size(); i++)
     //                           ^^^^^^^^
     {
         std:: cout << "x[" << i << "] = "<< x[i] << std::endl;
     }
}

Here is a live example. Notice, that std::array offers a size() member function which you may want to use instead of the sizeof operator.

Moreover, since std::array is a standard sequence container, you could iterate through its element this way:

 std::size_t i = 0;
 for (auto e : x)
 {
     std:: cout << "x[" << i++ << "] = "<< e << std::endl; 
 }

Here is a live example.