JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo">
    <span class="baz">I stay.</span>
    <span class="baz foo">I will be removed.</span>
    <span class="foo">I will be removed.</span>
    <span class="baz">I stay.</span>
    <span class="bar foo baz">I will be removed.</span>
</div>
<button>Remove</button>

JavaScript

$('button').click(function() {
    var form = document.getElementById('foo');
    var spans = form.getElementsByTagName('span'); // most cross-browser-compatible method
    for (var i = spans.length; i--;) {
        var span = spans[i];
        if (span.className.match(/\bfoo\b/)) {
            span.parentNode.removeChild(span);
        }
    }
});