JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/jquery-1.11.1.min.js"></script>
<form action="" method="post" id="myform" enctype="multipart/form-data">
    <input type="file" name="resume" id="resume">
    <input type="submit" value="submit">
</form>

JavaScript

var is_upload = 0;
var error = 0;

$("#resume").on("change", function (event) {
    is_upload = 1;
    error = 0;
});

$('#myform').submit(function () {
    if (is_upload == 0) {
        alert('Please upload your resume');
        error = 1;
        return false;
        
    }
});