Question

I have a program showing error. How to resolve the error and to use ostream to display output
I use g++ compiler in my ubuntu

#include<iostream>
using namespace std;
int main()
{
    ostream out;
    out<<"Hello World";
}

Answer 1

The ostream that you want (attached to the display) has already been defined as cout.

#include<iostream>
using namespace std;
int main()
{
    cout<<"Hello World";
}

Not all ostreams send the stream to the terminal display.