JSFiddle - React, Tailwind, and code Playground

HTML

<div id="second"></div>

CSS

#second { border: 1px solid blue; }
.single { background: cyan; border: 1px solid red; }

JavaScript

var valuesG = [], //array literal
    $elements = $(); //empty jQuery object

for (i=0; i < 100; i++) { //we don't have to query array length each iteration
    valuesG[i] = Math.floor(Math.random()*101); 

    //collect the elements into a jQuery object
    $elements = $elements.add($("<div class='single'>").css('height', valuesG[i]));
}

$elements.appendTo($("#second")); //insert to DOM once - much quicker