Probably a silly question, but the basic way I learned how to change CSS of something on click is

var x = document.getElementById("id"); 
    x.style.height = "auto"; 

or whatever.

But say I want divs of a certain class to change CSS attributes when clicked. But not all at the same time, only the one I just clicked. Adding separate ID’s and functions to each of them seems irrational.

Thank you!