JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <input type="text" /><br />
    <input type="text" /><br />
    <input type="text" /><br />
    <input type="submit" value="next" class="next" />
</div>
<div>
    <input type="text" /><br />
    <input type="text" /><br />
    <input type="text" /><br />
    <input type="submit" value="next" class="next"  />
</div>
<div>
    <input type="text" /><br />
    <input type="text" /><br />
    <input type="submit" value="next" class="next"  />
</div>

JavaScript

$('.next').click(function() {
    var empty = $(this).parent().find("input").filter(function() {
            return this.value === "";
        });
        if(empty.length) {
            //At least one input is empty
            alert("empty!");
        }
});