JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="input" />
<button id="test">test</button>

JavaScript

var input = $('#input');
var button = $('#test');

var r = new RegExp('^[a-zA-Z0-9\\]\\\\]*$');

button.click(function () {
    alert(r.test(input.val()));   
});