JSFiddle - React, Tailwind, and code Playground

HTML

<img id="i" onClick="fadeOutById()" src="http://placehold.it/100x100" style="opacity: 1"/>
<img id="e"   onClick="fadeOutById()" src="http://placehold.it/100x100" style="opacity: 0"/>

JavaScript

function fadeOutById() {
    var e = document.getElementById("i");
    var f = function() {
        e.style.opacity -= 0.01;
        if (e.style.opacity <= 0) return;
        requestAnimationFrame (f);
    };
    requestAnimationFrame (f);
}

function fadeInById(eid) {
    var e = document.getElementById(eid);
    var v = 0.01;
    var f = function() {
        v += 0.01;
        e.style.opacity = v;
        if (e.style.opacity >= 1) return;
        requestAnimationFrame (f);
    };
    requestAnimationFrame (f);
}