JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main"><div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div class="test">Splurge</div>
<div...

CSS

#main {
    width:600px;
}

JavaScript

console.time('Test1');
$('.test').each(function() {
   $(this).css('width', $('#main').css('width')); 
});
console.timeEnd('Test1');

console.time('Test2');
$('.test2').each(function() {
   $(this).width($('#main').width()); 
});
console.timeEnd('Test2');

console.time('Test3');
$('.test3').each(function() {
   $(this).width(parseInt($('#main').css('width'), 10)); 
});
console.timeEnd('Test3');