JSFiddle - React, Tailwind, and code Playground
HTML
<input type="checkbox" />
<br />
<input type="checkbox" />
<br />
<input type="checkbox" />
<br />
<input type="submit" value="Verwijder" />
JavaScript
$('input[type="checkbox"]').click(function () {
$("input[type=submit]").val("Delete " + $('input:checkbox:checked').length + " rows");
});