JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" id="test" />
<div id="result"></div>
CSS
.valid {
color: green;
}
.invalid {
color: red;
}
JavaScript
var regex = /^\d+-\d+$/;
$('#test').on('keyup', function () {
var text = $(this).val();
if (regex.test(text)) {
$('#result').text('Valid!').removeClass('invalid').addClass('valid');
} else {
$('#result').text('Invalid!').removeClass('valid').addClass('invalid');
}
});