JSFiddle - React, Tailwind, and code Playground

HTML

<p>Hover an element and refresh the page, than move your mouse away.</p>
<a id="elementA" class="el"></a>
<div id="element2" class="el"></div>

CSS

.el{
    width:200px;
    height:200px;
    margin:1px;
    position:relative;
    background:#ccc;   
    float:left;
}

JavaScript

var fromA = false;

console.log(fromA);
function handler(ev) {
    console.log(fromA);
    if (fromA) {
        var target = $(ev.target);
        var elId = target.attr('id');
        if( target.is(".el") ) {
           alert('The mouse was over'+ elId );
        }
    }
    fromA = false;
}
$("#element2").mouseover(handler);

$('body > :not(#element2)').mouseover(function () { 
    fromA = false;
});

$("#elementA").mouseleave(function() {
    console.log(fromA);
    fromA = true;
});