How can someone add events to a dom object?

Answer 1

elemen . addEventListener("click",function(event){
codes});

Answer 2

Just write the JS code and specify the dom object by id or class or tag

Answer 3

Suppose that you have a button with id="btn", here we get the element and add eventlisteners to it:

var btn = document.getElementById("btn");
btn.addEventListener("click", doOnClick);

function doOnClick() {
//do something
//and remember to remove the event listeners from the button
btn.removeEventListeners("click", doOnClick);
}