Question: I'm new to C++ and I keep getting a message saying something was not declared in the scope. How do I declare stuff in the scope?

This is a bit of code I wrote, when compiling I get the message that system and return0 where not declared in the scope, how do you fix the code? How do I declare stuff in the scope?

```
#include <iostream>

using namespace std;

int main()

{
    cout<<"hello";
    system("PAUSE";

    return0;
}

```

Answer: 
Firstly, you must add the include for `system`:

```
#include <cstdlib>  

```

Secondly you need to add a closing parentheses on the `system` call and then put a space between `return` and `0`. E.g.:

```
system("PAUSE");
return 0;

```

As has been suggested in the comments, the use of `system` is strongly discouraged. Reasons are listed in [this answer](https://stackoverflow.com/a/4622772/1517648)
`system()` is declared in `<cstdlib>`, and you're missing a `)` at the end of the function call.

`return0` should be `return 0`