Which of these four programs shows something? Say it before you run each one.

Plan. A function runs only when it is called, and a call needs the brackets.

1. Program 1 defines hello and calls it with hello(). It shows Hello once.
2. Program 2 writes hello without brackets. This only names the function. It does not call it, so nothing is shown.
3. Program 3 defines hello and never calls it. Nothing is shown.
4. Program 4 calls it twice. It shows Hello twice.