Q:

How to interact with Java Scanner Class

I am super newb with Java and I am trying simple codes with Atom editor (osx). 
Please, someone can help me to understand how can I interact with code with Atom?
I use Script package (Atom) to run the code (cmd+i).
For example if I use the Scanner class:
import java.util.Scanner;
public class Les {

    public static void main(String[] args) {

         String s;
         Scanner in = new Scanner(System.in);
         System.out.println("Enter a string");
         s = in.nextLine();
         System.out.println("You entered string " + s);
    }
}

the output will be "enter a string"
Where I can insert the Strings?

A:

That is not a final output. It is the first line ("Enter a string") that you printed. Further, you have to type some value under this message in your console (I wrote "hello") and press Enter. After all this, you will see your last message (I got "You entered string hello").
In the console, it will look like
Enter a string
hello
You entered string hello

