The "() =>" part of EventListener was never explained.

Thank you, Steven. I didn't go through that route. I only got here because Javascript and the DOM was a requirement for the next course in my FEWD program.

To be clear, this: button.addEventListener('click', function() { p.innerHTML = input.value + ':'; });

Is the same as: button.addEventListener('click', () => { p.innerHTML = input.value + ':'; });

Interesting to define an empty function within addEventListener. I understand it a little better after some google-fu.

How common is a function that's written this way? var.addRandomFunction('trigger', function() { code = 'do this stuff'; });

The last part of this is also confusing: "});".

But I understand it enough now to not be completely confused whenever I see it, thanks. I'm sure I will go over this again during the rest of the Javascript training in FEWD and if not I will take note to review this again.

In that "`});" at the end, the "}" is the closing brace of the anonymous (unnamed) function, the ")" is the closing parenthesis of the "addRandomFunction" call, and ";" is the normal end of any JavaScript statement.