JSFiddle - React, Tailwind, and code Playground

by David Joseph Guzsik

HTML

<div style="opacity:0.1;">0.1</div>
<div style="opacity:0.2;">0.2</div>
<div style="opacity:0.3;">0.3</div>
<div style="opacity:0.4;">0.4</div>
<div style="opacity:0.5;">0.5</div>
<div style="opacity:0.6;">0.6</div>
<div style="opacity:0.7;">0.7</div>
<div style="opacity:0.8;">0.8</div>
<div style="opacity:0.9;">0.9</div>

CSS

div {
    background-color: #000;
    width: 100px;
    height: 100px;
    color: #fff;
}

JavaScript

var currentOpacity;

$("div").hover(function() {
    currentOpacity = $(this).css('opacity');
	$(this).fadeTo('fast', 1.0);
},function(){
	 $(this).fadeTo('fast', currentOpacity);
});