Seven circles but only one is changing colour, why?

Question

I am new to javascript and I have an assignment to create seven circles which should change colour on a mouse click. The first circle is changing colour but the other six just r

Answer 1

id attributes are for referencing single Items, while Class attributes are for referencing group of items..

so changing ID to Class would look like this.. -

and then you get the group of items by their class name using this..

var circle = document.getElementsByClassName("circle1");