What is the different between n = 1 + 2 and n = “1” + “2”? If you were to display the contents of n, what would be shown on your page for each instance of n?
The first case of n is adding two numbers together, which will output "3". The second case of n is concantonating strings, which will output "12".
This means that you take the var that comes before the += and add it to itself plus the var behind the +=. It's just a consied way of saying "x = x + y"
assuming you entered "x+=y". It is not just used for numbers; it can also be used for strings. We used it for concantonating strings during the counting loop.
by adding ".innerHTML = ". To the end of it you can have it change the value of a the HTML element.