JSFiddle - React, Tailwind, and code Playground
HTML
<span id="someid">check this phrase </span><br>
<span id="result"></span>
JavaScript
var mystring = $("#someid").text();
$("#someid").click( function (event) {
if(/\s+$/.test(mystring)) {
$("#result").text("space");
}
else
{
$("#result").text("no space");
}
});