II am learning to do stacks.
And I have downloaded the following code online.
My question is how do I move the JAVA SCRIPT function into a java script file, and what code and how to call and enable the code (function) when it's not all in the HTML file in the stack.
<! DOCTYPE html>
Click the button to trigger a function that will output "Hello World" in a p element with id = "demo". </ P>