JSFiddle - React, Tailwind, and code Playground

HTML

<div id="txt1">txt1</div>
<div id="txt2">txt2</div>
<br/><div id="btn">btn</div>

CSS

body {
    background-color:#666;
    color:white;
    font-size:20px;
    margin:20px;
}
#txt2 {display:none;}

JavaScript

var cur = 1;
$('#btn').click(function() {

    if (cur == 1) {
        $('#txt1').fadeOut(500, function() {
            $('#txt2').fadeIn(500);
        });
        cur = 2;
    } else if (cur == 2) {
        $('#txt2').fadeOut(500, function() {
            $('#txt1').fadeIn(500);
        });
        cur = 1;
    }
});