Missing text

[SomeCodingNoob]

More basic practicing codes I'm afraid. I've made a little thing to double a number designated by the user but the actual text that should be showing (apart from "Enter x value: ") isn't appearing. I'm just getting "Enter x value: ", then when I input 5 I get 10 back on the next line. Any thoughts?

  #include <iostream>

int doubleNumber(int x)
{
    using namespace std;
    cout << "Enter x value to be doubled: " << endl;
    int x;
    cin >> x;
    return x * 2;
}

int main()
{
    using namespace std;
    int x = -1;
    cout << "Double x is: " doubleNumber(x) << endl;
    return 0;
}

[EwCjE3v7]

You have a few errors above:

#include <iostream>

int doubleNumber() // take useless int x away
{
    using namespace std;
    cout << "Enter x value to be doubled: " << endl;
    int x;         // if we had the variable x above, then this would be in error
    cin >> x;
    return x * 2;
}

int main()
{
    using namespace std; // u may wanna define this in the global scope
    // useless int, can be removed
    cout << "Double x is: " << doubleNumber() << endl; // You forgot the '<<' operator in the middle.
    return 0;
}

C++ Shell: http://cpp.sh/32t

Many useless stuff up there, I have removed them and also you missed a '<<' operator.

[SomeCodingNoob]

Thanks very much for the help, what do you mean by global scope? (I'm still very new to coding)

[AbstractionAnon]

Global scope means visible to the entire translation unit. As you have it, using namespace std; is only visible within your functions. By putting it at line 2, you don't need to include it within each function.

[SomeCodingNoob]

Ah that makes sense, thanks again!

[Chervil]

You might also have done this, to make use of the x declared in main() by passing it as a parameter to the function. Note that the variable name used doesn't have to be the same in function doubleNumber() as in main()

#include <iostream>

using namespace std;
    
int doubleNumber(int n)
{   
    return n * 2;
}

int main()
{
    int x = 0;
    cout << "Enter x value to be doubled: " << endl;
    cin >> x;
    cout << "Double x is: " << doubleNumber(x) << endl;
    return 0;
}