JSFiddle - React, Tailwind, and code Playground

HTML

<div id="one-by-one">
    <div>One</div>
    <div>Two</div>
    <div>Three</div>
    <div>Four</div>
</div>

JavaScript

$("#one-by-one").children().hide();
var oneByOne = function(arr) {
    $el = $(arr.shift());
    $el.fadeIn(600, function() {
        if (!$el.next().length == 0)
            oneByOne(arr);
    });
};

arr = $("#one-by-one").children().get();
oneByOne(arr);