JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" maxlength="2" />
<a href="#">Validate</a>

JavaScript

$("a").click(function() {
    $input = $("input");
    console.log($input.attr("maxlength"), $input.val().length);
    if ($input.attr("maxlength") != $input.val().length || !/^\d+$/.test($input.val())) {
        console.log('failed');
    } else {
        console.log('passed');
    }
    return false;
});