JSFiddle - React, Tailwind, and code Playground
HTML
<form method="post">
<div class="row requiredRow">
<label for="email" id="email-ariaLabel">Your email address:</label>
<input id="email" name="email" type="email" class="required" title="This is a required field" /> <span class="msg error">Not a valid email address</span>
<span class="msg success">A valid email address!</span>
</div>
</form>
CSS
.msg {
display: none;
}
.error {
color: red;
}
.success {
color: green;
}
JavaScript
$('#email').on(keyup, function () {
var email = $(this).val();
var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/igm;
if (re.test(email)) {
$('#email').addClass('error');
} else {
$('#email').removeClass('error');
$('#email').addClass('success');
}
});