JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" name="inputName" id="inputName" />
<input type="text" name="inputEmail" id="inputEmail" />
<input type="text" name="inputTel" id="inputTel" />
<input type="submit" value="Submit Form" disabled/>

JavaScript

var toValidate = $('#inputName, #inputEmail, #inputTel'),
        valid = false;
    toValidate.keyup(function () {
        if ($(this).val().length > 0) {
            $(this).data('valid', true);
        } else {
            $(this).data('valid', false);
        }
        toValidate.each(function () {
            if ($(this).data('valid') == true) {
                valid = true;
            } else {
                valid = false;
            }
        });
        if (valid === true) {
            $('input[type=submit]').prop('disabled', false);
        }else{
            $('input[type=submit]').prop('disabled', true);        
        }
    });