JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <input type="text" id="inputField" value=""/> 
    
</div>

CSS

.something {
    width: 100px;
    height: 100px;
    border: 1px solid #000;
}

JavaScript

function start() {
    var inputField = document.querySelector('#inputField');
    // Works if addSomething() is commented out.
    addSomething();
    console.log(inputField);
    doSomething(inputField);
}

function addSomething() {
    var container = document.querySelector('#container');
    var div = document.createElement('div');
    div.className = 'something';
    container.appendChild(div);
}

function doSomething(el) {
    el.value = 'Some random input';
}


start();