xxxxxxxxxx
let test = document.getElementById("test");
test.addEventListener("mouseover", function( event ) {
alert("mouse over test!")
, false);
xxxxxxxxxx
// hover in
element.addEventListener("mouseover" , function )
// hover out
element.addEventListener("mouseout" , function )
xxxxxxxxxx
It is wrong syntax.
Here is the correct one.
let test = document.getElementById("test");
test.addEventListener(
"mouseover",
function (event) {
alert("Mouse over btn!");
},
false
);